Ever-newer waters flow on those who step into the same rivers.

First of August 2015. I am just outside the Cloister at the medieval Abbey of Silvacane in La Roque d’Anthéron, France. I’m about to begin a solo piano recital by playing Philip Glass’s Metamorphosis 2. I’ve performed this piece many times. I expect to be able to play the music well, yet usual pre-concert anxiety and exhilaration are affecting me.

I’m not a drug addict. Yet, many times each year I get a fix, strong stimulants flow through my body. I give concerts. And almost always, through fear, public performance brings me to heightened consciousness. Adrenaline makes me intensely aware, and perhaps more able to play well. Accounts here, of my performances of American minimalist composer Philip Glass’s solo piano piece Metamorphosis 2, regard specific performances that occurred at the times and places mentioned. With words, I might evoke the regularly repetitive yet never-the-same task of the performer of scripted music—each repetition continuing a line made from more and more loops, more and more passes through pre-existing musical text. Metamorphosis 2 contains multiple literal repetitions of material, concentrating the opposition/balance of sameness and variety present in the performer’s repeating of any music. As hand and fingers find increasingly efficient ways through a piece of music, the performer may also find artistic insight. Though not necessarily sought, analytic awareness may arise through the process of repetition, and in the laboratory of the concert.

A piece of scripted music—conventionally notated western classical music—is greatly variable in playing. Even played by the same solo pianist over and over and over, a piece of music will emerge differently at each instance, each iteration. Each piano has particular tuning, timbre, and sustaining capabilities. In terms of conventional piano playing, pitch adjustment remains outside the player’s control. What varies noticeably from performance to performance are phrase organisation, inflection, tone, tonal balances, and matters regarding time, rhythmic proportions, the nature, speed and pacing of beat. The acoustics of the concert space will affect the way sounds sustain and how they are perceived by the audience and the performer, and this will affect the performer’s work. The physical responsiveness of a particular piano will strongly influence the actions/reactions of the pianist, and the seemingly unchosen nuances that occur in performance. In my opinion, the specific audience present at a concert can affect the music that is made. Music is a group activity. The collective scrutiny of many listening ears alters the musical and artistic awareness of each person—including the performer.

The word commonly used in the French language to signify practising a musical instrument is “repetition”. Rehearsal coaches in opera houses are called “répétiteurs”. Surely the understood sense of this language is that in repetition change arises, improvement or progress. It is not exact or literal repetition. “Re-peat” is based on the Latin word “petere”, and so, “to seek” again. From the time of Walter Benjamin’s analysis or earlier, the understanding of artistic repetition changed.2 In the postmodern, industrialised world—a world of mass production—a repeated product or recording is clone-like. The presence of near-exact copies is a pervasive feature of present-day manufacturing and life experience. The nature of repeating a performance, and the desire to do so, may have been very different in the pre-industrial world.

Twenty-eighth of July 2015. I’m sitting in the Green Room on the eighth floor of Broadcasting House in London. In about 15 minutes, I’m going to play Philip Glass’s Metamorphosis 2 on the BBC programme In Tune, a daily live show on Radio 3. I’ve already tried the piano in the studio, a Hamburg Steinway C, and chatted a bit with the interviewer. After my playing, we will talk on the air. I’ve been asked if I will read a question that’s part of a UK-wide competition. The winner receives tickets to a BBC Proms concert.

Repetition can give an appearance of order. Musicians are accustomed to repetition. Even music that isn’t especially repetitive is subject to considerable repeating in a musician’s life. One month, as an adolescent pianist, I began each day’s practising by playing through “cold” (without warming up) Chopin’s “Black Key” Etude, opus 10, number 5. Replaying is our practice, a structuring of time, and, for the player, a structuring of life. In making a repertory, musicians strike a balance between repeating material and exploring new material. Some pianists play a huge number of pieces. Others delve into a few. How many times, and in how many ways, did the celebrated pianist Ignacy Jan Paderewski perform the “Moonlight” Sonata? Or rock music icon Mick Jagger sing “(I Can’t Get No) Satisfaction”?

Repetition is a form of change.
Brian Eno and Peter Schmidt3

In 1966, pianist Glenn Gould described the change he believed was occurring in the musical performer’s work. After producing a repeatable sound recording,4 a musician need not perform the same music over and over and over:

Conceivably, for the rest of his life he will never again take up or come in contact with that particular work. In the course of a lifetime spent in the recording studio he will necessarily encounter a wider range of repertoire than could possibly be his lot in the concert hall… It permits him to encounter a particular piece of music and to analyze and dissect it in a most thorough way, to make it a vital part of his life for a relatively brief period, and then to pass on to some other challenge and to the satisfaction of some other curiosity. Such a work will no longer confront him with a daily challenge. His analysis of the composition will not become distorted by overexposure, and his performance top-heavy with interpretive “niceties” intended to woo the upper balcony, as is almost inevitably the case with the overplayed piece of concert repertoire.5

Thirtieth of May 2015, Wuhan, China. I’ve been backstage at the new Qintai Concert Hall for a couple of hours. Coming back here from the hotel this afternoon, traffic was much heavier than traffic this morning. Tonight’s concert includes a number of musicians from the festival that I’ve been part of this week. I am going to play a single piece: Philip Glass’s Metamorphosis 2. In my playing of the piece, two passages that used to seem technically graceless are much easier to play now.

In recent years, I have given many performances of repetitive piano music by Philip Glass. In the playing of phrases or whole sections of repeated material—material that is notated without variation—I welcome some changes of emphasis or rhythmic inflection in the performance. It’s a delicate, even precarious balance. Wilful changes are garish, too noticeable. Yet, small irregularities of the human hand and mind lead to a changeable musical surface that offers differing and desirable musical experience, in comparison, for example, to precisely unvaried automatic rendering by a machine. I may discern the differences as they happen in my playing, rather than trying consciously to make differences occur. Tone, rhythm, inflection, use of the piano’s pedals—are in a relationship so interdependent that I imagine my mental state as what Sigmund Freud describes as “gleichschwebende Aufmerksamkeit”,6 often translated in English as “evenly divided attention”. Freud suggests this is the ideal mental state for the psychiatric analyst.

In the parlance of mechanical player-pianos, “hand-played” described a piano roll that was derived from a real-time human performance. After initial punching, the roll could be retouched. (A long roll of paper punched with patterns of small holes causes keys on the player-piano to play, as the paper passes across a “tracker bar”.) Alternatively, an entire roll could be prepared by directly punching holes, measuring physical distances on paper to make rhythm—no piano playing required. Beginning in the 1940s, composer Conlon Nancarrow took the rhythmic possibilities of piano-roll punching to mathematically complex, superhuman extremes in his studies for player-piano. In today’s electronic music, especially in dance music, repeating patterns, or loops, generated by a computer may be extremely regular and regularly repetitive, down to the level of milliseconds or frames. The boundary-defying musician Francesco Tristano has described his preference for playing repeated loop-like material live on the piano,7 hand-played, while many computer programs that produce musical rhythms include possibilities for mimicking the irregularities of human playing.

Today, “music” signifies recorded music. Live music is not the norm; the adjective “live” has become necessary. We are arriving at a new understanding of recording (already reached in some pop music). Recently, I participated in a recording session of a chamber music piece that I never played continuously from beginning to end. Yet, sufficient material was captured to assemble an intimate, improvisatory, and ephemeral-seeming performance. Perhaps, such a process is like film-making. Film actors do not perform a script from start to finish. The American actor Julianne Moore said:

I really know my lines. I really think about what I’m gonna do. Sometimes people think that means I’ve already played the part in my head. That’s not true. I know the parameters. Then, when the camera goes on, I’m ready to have an experience. I don’t want it to happen in my living room. I want it to happen on camera.8

My goal in practising for this recording had little to do with preparing a coherent beginning-to-end reading of the entire piece. My interest was in achieving spontaneous, vivid line-readings through one- or two-minute sections of the piece—“correct”, but generally played with more uncertainty and more risk of failure than I would tolerate in a concert. In post-production, attention can be paid to coherence and overall continuity.

After a “take” in a recording session, I often find it desirable to continue recording again right away. The chance of achieving very similar rhythmic treatment and phrase shaping that can match well with earlier takes seems to diminish as minutes elapse. Today, classical performers, in their live playing, seem ever more easily able to repeat musical material with great sameness of detail and expressive nuance. Is this an outcome of the use, or existence of sound recording? Is the generally increasing instrumental proficiency of classical performers an outcome of the prevalence of recorded sound?

Fourth of April 2008. I’m backstage at the Harris Theater in Chicago. Tonight, I’m playing in a gala performance with Hubbard Street Dance Chicago. Alejandro Cerrudo has choreographed a piece that utilises recordings of piano pieces including my recording of Philip Glass’s Metamorphosis 2. For tonight’s performance, I will play the music “live”. In our first rehearsal, the dancers were surprised. My playing didn’t correspond exactly to my commercial recording of Metamorphosis 2, the precise rhythmic nuances of which they had absorbed in their limbs. Hearing a few phrases from the recording, I recognised the playing as mine, but barely.

In earlier times, the presence of human musicians was required in order for music to be heard. Now, pervasively, we have playback of recorded music. My chamber music coach, the violist Paul Doktor said, “Never twice the same!” It was a Middle-European mantra of chamber-music playing. Consider legions of musicians playing the same texts over and over and over—but never in exactly the same way. The repeated playing of a sound recording yields a more precisely repeated sonic result.

At every moment there is an infinity of perceptions in us, that we do not reflect upon or notice, these are alterations in the soul itself, of which we are unaware because these impressions are either too minute and too numerous, or else too unvarying, so that they do not distinguish themselves individually, But when they are combined with others they do nevertheless have their effect…
Gottfried Wilhelm Leibniz9

Classical performers have differing views of repeated performance. The pianist Van Cliburn maintained that after arriving at a satisfying interpretation of a particular piece of music he did not want to change it.10 He intended to achieve the same reading in every subsequent performance. Cliburn said: “If I learn something, it’s not to play for this week or that week, but forever.”11

Alastair Macaulay describes something quite different from Cliburnian Platonism. Macaulay recounts his impressions of watching on film the evolving performance of Janet Baker as she sang the role of Vitellia in Mozart’s La Clemenza di Tito:

The revelation of repeated viewings was to discover how, each season, Ms. Baker’s musical and physical manner changed… In 1974, when the production was new, Ms. Baker was possessed of many kinds of stillness. In Act I, the way she listened balefully to Sesto… was deadly; in Act II, the way she stood still for “Non più di fiori,” singing it in blanched, resigned tones (virtually monochrome), was supremely poignant.

Yet, in 1975, Ms. Baker drenched that same aria in a wide palette of colors while seeming racked by her own vocalism. I can’t forget how, apparently now incapable of stillness, she kept clutching her hands together and transferring weight from foot to foot — as if possessed by the need to transmit this new range of nuance. In 1976, she had changed again. Then she seemed in full physical control, but played the role — that aria, above all — with a marvelously heroic supply of period gestures, weighted and forceful, evoking Racine tragedy…12

Twenty-third of October 2001. I am in my dressing room at Alice Tully Hall in Lincoln Center. The first music I’m playing tonight will be Metamorphosis 2 by Philip Glass. I am curator of, and principal performer in the annual Irene Diamond concert, honouring one of the Juilliard School’s important benefactors. It is my first concert since the World Trade Center attacks. Some parts of the event, like the dinner that precedes the Diamond Concert, were more subdued than usual, in keeping with New York City’s collective sombre mood. The concert includes first performances of chamber pieces by Nico Muhly and Kati Agocs that I commissioned for this event.13

Was Glenn Gould right? Do multiple performances of a scripted piece by a player lead to “overexposure” and a performance “top-heavy with interpretive ‘niceties’ ”? Often-played pieces may wander from denotative reading of the text. But the function of a musical text may not be simple representation.

When I started working on Morton Feldman’s duo For Christian Wolff, I aimed to learn the notated rhythms accurately. The published score is a reproduction of Feldman’s hand-written musical text. Some things puzzled me. There are measures that don’t add up to the expected number of beats—mistakes? In other measures, the flute part and the keyboard part are not rhythmically aligned visually. Perhaps, in performing For Christian Wolff, fastidious coordination of beat between flute and keyboard is not necessary?

The classical music community tends to share the belief that pitches and rhythms written by a composer ought to be performed accurately. There are many views regarding the specificity and nature of that accuracy.14 In the playing of difficult new music, getting the pitches and rhythms “right” can be challenging or impossible to achieve. I imagine first performances of The Rite of Spring and Beethoven’s Ninth Symphony, indeed, every symphony by Beethoven. By today’s standards of accuracy, it seems likely that those performances were deeply flawed. As musicians struggled to bring coherence to a complex piece by Milton Babbitt, he quipped, “Life is short and my piece gets long”.15 Apparently the players could not go fast enough for the music fully to make sense. I first became aware of Debussy’s D’un cahier d’esquisses by listening to a recording of the music by pianist Walter Gieseking. Later, looking at the notation of the piece, I realised that Gieseking read a note in the penultimate measure as if it was written in treble clef; it’s a bass-clef note. I rather liked the “F” that Gieseking played, and in my ear it had primacy.

Do the notes in a written composition represent what the listener will hear? Or does written music merely put the performer into a condition for making music? The composer Brian Ferneyhough writes:

What can a specific notation, under favourable conditions, hope to achieve? Perhaps simply this: a dialogue with the composition of which it is a token such that [the] realm of non-equivalence separating the two (where, perhaps, the “work” might be said to be ultimately located?) be sounded out, articulating the inchoate, outlining the way from the conceptual to the experiential and back.16

And then, the effects of a notation (fixed in writing) change, as new generations of musicians read it (repeat it). The resulting music necessarily changes, and keeps changing. So it is in reading every sacred text. Even if the symbols remain the same, their signification (what they signify) does not remain the same. For much of my life as a classical music performer, I believed that a mistake-filled performance of a piece was not really the piece. A performance either was the music or it wasn’t. Now, I have a different belief. All the sounds that result from a written piece (a musical text) are the piece. All performances of that piece ever given add up to the identity of that music. Such a range of results represents a limit of all possible musics that might be made. In this way, a composition is never finished but always subject to further completion, repetition, understanding, reading, misreading, exploration, and mistake. Each repeating adds to the totality, re-centring it. And repeats, at least “hand-played”, cannot be identical.

During one month, Paula Robison and I gave four performances of For Christian Wolff, at the Isabella Stewart Gardner Museum in Boston. Later, listening to the recordings that were made of each performance, it seemed to me that some of the most satisfying music-making occurred when we were not “together” in a conventional sense. We did or didn’t do what the notation represents.

Eighteenth of October 2013. I am offstage at La MaMa in New York City, waiting for my cue to enter the stage and begin playing Philip Glass’s Metamorphosis 2. I’ve played this music many times. I’m fairly confident of being able to play it adequately, yet usual pre-performance anxiety and exhilaration are affecting me. I repeat this sensation of adrenalised awareness many times each year. In this show, I collaborate with the dancer/movement artist Maureen Fleming. Tonight is the official opening night of our twelve-performance run. Last night, I was here for the preview performance. This morning I had to be in Boston—so some quick travelling. I arrived back in New York at the theatre before 5 p.m. In this production, the recorded voice of Ruth Maleczech is heard. The text begins with the words: “What would be the point in remembering.” This text is repeated several times, with varying emphasis. It’s almost formulaic, as Maleczech lands on one word (“What…”) and then another (“point…”), then another (“…remembering”); the shifting implications are vivid. Many years ago, Ruth directed me in a show in Boston, in which I played music onstage. As I hear the recording of her voice repeating this text each night, I remember performing in Boston.

The pianist and statesman Ignacy Jan Paderewski played Beethoven’s so-called “Moonlight” Sonata very many times. It was a feature of his public programmes for decades. I have speculated about how many times Paderewski might have performed the piece… (He can be seen and heard playing part of it in the 1938 feature film Moonlight Sonata.) How many pianists have played this music? How many times has it been repeated? The Moonlight Sonata is in the 1936 French talking-picture Un grand amour de Beethoven, directed by Abel Gance, in Gus Van Sant’s film Elephant made in 2003, and in dozens of other films. At the present moment, right now, how many people are repeating the Moonlight?

Twentieth of October 1998. I’ve just come offstage at Miller Theatre at Columbia University in New York. My programme finished with John Adams’s Phrygian Gates. Now I’m going to play an encore,17 Philip Glass’s Metamorphosis 2. Tonight’s performance is a collaboration between theatre director Ian Belton, lighting designer Ben Kato, and me. The show contains sound effects, voice-overs—a reimagined concert experience, we hope.

It may be that the taste for, and value of repetition varies as place, time, or context alters. In a world without mechanical reproduction, before mass production, the steady hand of the craftsman repeating a design, making a chair or a fork, very consistently, over and over and over, was highly esteemed. In our world where exact reproductions are prevalent and inhuman, our sense of the value of human irregularity may intensify.

Increasingly precise repetition of musical performance was facilitated by the strong, regular beat that became pervasive in the performance of classical music by the later twentieth century. Over a period of more than a hundred years, ensemble players became better able to stay together. Conductors became adroit in beating very regularly. The rise of the symphony orchestra, with its increasingly intricate large-scale repertory, brought great change. Orchestral players of the eighteenth and early nineteenth centuries primarily played opera; the playing of symphonies was rare. The basic musical experience of those earlier players and conductors was accompanying singers, accommodating the delivery of a sung text.

Increasing beat-regularity was, I believe, the outcome or reflection of several musical and societal changes: mass production, the standardisation of time keeping, time zones, the metronome, sound recording, the ascent of conducting, full scores, the practice of rhythmic “subdividing” by performers, and even notions of an egalitarian society. There was widespread accommodation of old music to highly regular repetitive beat. Arnold Schoenberg’s 1948 article describes the great change that was occurring. He writes:

Almost everywhere in Europe music is played in a stiff, inflexible metre—not in a tempo, i.e. according to a yardstick of freely measured quantities… A change of character, a strong contrast, will often require a modification of tempo. But the most important changes are necessary for the distribution of the phrases of which a segment is composed.18

Discussing a piece he aspired to conduct, Schoenberg writes, “It seemed to me as if the conductor has taken a wet sponge, erasing all traces of problems by playing whole movements in one stiff, inflexible tempo.”19

So, classical music was remodelled, regularised, and made more regularly repeatable.

Twenty-fourth of October 1996. I’m offstage at St. Mark’s in Greenwich Village in New York City. I’m about to play a piece by Philip Glass that I have just learned—Metamorphosis 2. This is part of a dance performance with dancer/choreographer Polly Motley. At each performance, I need to find the precise speed necessary for the dancers. After Duet, set to Metamorphosis 2, there is a longer piece, in which I will take phrases from Glass’s music as material for extemporising.

The balance or opposition of variety and sameness is a dichotomy providing essential friction in a lot of art. Personal preference for variety or sameness may lead to preference for a stylistically varied concert programme, or the grouping together of similar pieces. It may explain why some performers learn many new pieces and others repeat only a few. And this preference may have to do with place and time. If linear thinking is no longer possible, as Marshall McLuhan assessed it,20 perhaps sameness is more a virtue now? If linear thought and experience prevailed in the past, variety might have captured attention. If the allatonceness21 of today threatens to overwhelm, then sameness can compel.

I’m hearing another pianist’s YouTube recording of Philip Glass’s Metamorphosis 2. Though the familiarity of the music is striking, another aspect of the experience is how much I am surprised. I’m constantly comparing these recorded sounds that emanated from another performer to my mental store of what’s what. The new details are not revelatory or illuminating necessarily—nonetheless, the shock of the new joins with the familiarity of the repeat.

Can it be denied that with our repetitive acts we measure our way towards death—one tennis match, one car ride, one meal, or one performance of Beethoven’s Moonlight Sonata at a time? With concerts, the public performer of scripted music ritualises such increments. For the musician, the playing of a particular piece may be associated with a particular period of time, or particular places. A piece of music may disappear from the player’s repertoire, or keep recurring over and over and over. I am planning to perform Metamorphosis 2 again on 29 January 2016, 30 January 2016, 31 January 2016, 1 February 2016, 3 February 2016…

End notes

1. “ποταμοῖσι τοῖσιν αὐτοῖσιν ἐμϐαίνουσιν, ἕτερα καὶ ἕτερα ὕδατα ἐπιρρεῖ.” This is repeated by Plato. The reference comes down to us in many forms and with embellishments. It appeals to me that such an idea, apparently a parable of change, can be repeated so frequently and in so many ways. 

2. Benjamin, Walter. The Work of Art in the Age of Mechanical Reproduction [Das Kunstwerk im Zeitalter seiner technischen Reproduzierbarkeit (1936)]. Translated by Harry Zohn. In Illuminations: Essays and Reflections. Hannah Arendt (ed.). New York: Harcourt, Brace. 1968. https://www.marxists.org/reference/subject/philosophy/works/ge/benjamin.htm (Accessed 2015-09-07). 

3. Eno, Brian, and Schmidt, Peter. Oblique Strategies. 1975. http://www.rtqe.net/ObliqueStrategies/Ed1.html (Accessed 2015-09-05).

4. Mechanical sound recording existed well before recordings were made that could be played back. Already in the 1850s and 1860s, Édouard-Léon Scott de Martinville made sound recordings with the “phonoautograph.” See the work of the First Sounds research group: http://www.firstsounds.org/research/scott.php (Accessed 2016-01-24). 

5. Gould, Glenn. The Prospects of Recording. Reprinted from High Fidelity 16. no. 4. 1966. In The Glenn Gould Reader. Tim Page (ed.). Toronto: Lester & Orpen Dennys. 1984. pp. 335-336. 

6. Freud, Sigmund. Ratschläge für den Arzt bei der psychoanalytischen Behandlung (1912). In Gesammelte Werke—Chronologisch geordnet 8. Frankfurt am Main: Fischer. 1999. p. 376.

7. Tristano, Francesco. Red Bull Academy Lecture: Francesco Tristano [Video]. http://www.redbullmusicacademy.com/lectures/francesco-tristano (Accessed 2015.09.07). 

8. Quoted in Lahr, John. The Sphinx Next Door: Julianne Moore and her imagination. The New Yorker. 21 September 2015. http://www.newyorker.com/magazine/2015/09/21/the-sphinx-next-door-profiles-john-lahr (Accessed 2015-09-16). 

9. “Il y a à tout moment une infinité de perceptions en nous, mais sans aperception et sans réflexion, c’est-à-dire des changements dans l’âme même dont nous ne nous aperçevons pas, parce que ces impressions sont ou trop petites et en trop grand nombre ou trop unies, en sorte qu’elles n’ont rien d’assez distinguant à part, mais jointes à d’autres, elles ne laissent pas de faire leur effet…” Translation by the author. In Gottfried Wilhelm Leibniz. Nouveaux Essais sur l’entendement human. Paris: Flammarion. 1921. pp. 9-29. https://fr.wikisource.org/wiki/Nouveaux_Essais_sur_l’entendement_humain/Avant-propos (Accessed 2015-09-07). 

10. Stearns, David Patrick. Van Cliburn and his fraught generation. Condemned to Music (blog). Arts Journal. 2013.02.28. http://www.artsjournal.com/condemned/2013/02/van-cliburn-and-his-fraught-generation/ (Accessed 2015-09-07). 

11. Quoted in Beigel, Greta. Finally, a Return Engagement: Pianist Van Cliburn is hitting the concert trail… Los Angeles Times. 3 July 1994. http://articles.latimes.com/1994-07-03/entertainment/ca-11419_1_van-cliburn (Accessed 2015-09-06). 

12. Macaulay, Alastair. Janet Baker’s Voice, a Singular Instrument, Lingers Like No Other. New York Times. 13 August 2015. p. C1. http://www.nytimes.com/2015/08/13/arts/music/janet-bakers-voice-a-singular-instrument-lingers-like-no-other.html (Accessed 2015-08-31). 

13. My work with Nico Muhly eventually led to Haydnseek, a collaborative project in which my live performances of piano sonatas by Franz Joseph Haydn were overlaid, contextualised, and sometimes drowned out by new electronically-synthesised sounds. 

14. In a non-conventional reading, I made Bruce Brubaker’s Mahler’s Ninth Symphony. The piece is a piano quartet fashioned from my favorite simultaneities taken, in order, from the last movement of Gustav Mahler’s Ninth Symphony. 

15. In Babbitt: Portrait of a Serial Composer [Film]. Robert Hilferty (dir.). 2009. https://youtu.be/sf_Zfpq3gqk (Accessed 2015-9-4). 

16. Ferneyhough, Brian. Aspects of Notational and Compositional Practice (1978). In Collected Writings. James Boros and Richard Toop (eds.). Amsterdam: Harwood, 1995. pp. 7-13. 

17. In the United States, the French word “encore” is used to designate an added piece played at a concert after the announced or printed programme. In France and elsewhere in Europe, such an additional piece is termed a “bis”. Usually, in today’s practice, encores are not pieces already played in the concert. Sometimes, however, they are pieces already played in the concert… 

18. Schoenberg, Arnold. Today’s Manner of Performing Classical Music. In Style and Idea: Selected writings of Arnold Schoenberg. Leonard Stein (ed.). Berkeley and Los Angeles, CA: University of California, 1975. pp. 320-21. 

19. Schoenberg, p. 323. 

20. McLuhan, Marshall, and Fiore, Quentin. The Medium is the Massage. Jerome Agel (prod.). New York, NY: Bantam. 1967. p. 63. https://designopendata.files.wordpress.com/2014/05/
(Accessed 2015-09-08). 

21. McLuhan’s evocative term.