Contrary to the common negative characterization (see part III), improvisation as expressed in jazz involves a high degree of prepared and calculated musical ideas. All too frequently we hear the rather pejorative comment that in jazz it matters not what note one plays given the dissonance prevalent in jazz and its penchant for non-resolution. Though perhaps in some expressions of jazz such a remark might ring true, on the whole it tends to paint a rather misleading picture. A more accurate account is that jazz improvisers are intensely aware of what notes they play, when to play them, and for what reason this note or that scale should be played as opposed to others. For example, consider the common harmonic structures in which one finds purposely altered harmonies, i.e., dissonances that are deliberately applied to certain chord structures. One of the first skills that a beginning improviser learns is that most traditional jazz pieces consist of what is called the ii-V-I harmonic progression. For example, in the key of C major, the ii-V-I progression is: D minor 7 – G7 – C major 7. Because the V7 (or dominant 7) chord has multiple functions-e.g., it can serve as a transition chord into another key or as a common way to resolve back to the tonic key-it is a top candidate for harmonic alterations. Why? It is the chord that either leads us directly to a resolution back to the tonic key, or it functions as a transition chord to take us to a new key that will then serve as a temporary resolution of sorts. Given these functions, as opposed to being a “place of rest” (such as the tonic chord) or even a “temporary rest stop,” altering or extending its “normal” harmonies heightens the tension by adding new tonal colors into the mix. Jazz musicians are deeply aware of these possibilities, and maximize the tension-release motif in their solos. In fact, it is a common practice among jazz musicians to have numerous altered patterns prepared in advance-patterns which they have practiced for hour upon end in all twelve keys (and modes) so that when performance time comes, the music has become such a part of them that it flows effortlessly from them. Thus, it is in no way the case that jazz musicians simply fumble around, pulling notes out of thin air, rebelliously disregarding the harmonic structure of the piece because they have some kind of perverse attraction to dissonance for its own sake. While this might de-mystify jazz improvisation to a certain extent, it does not eradicate that side of jazz that involves a strong degree of spontaneity and communal interplay. In other words, mystery is still alive and well in the art of jazz improvisation because no matter how many patterns one has prepared in advance, the dynamism and community of jazz makes it such that in Heraclitean fashion, “no pattern is ever played exactly same way twice”; yet, the patterns are quite identifiable, as is the piece itself.
If jazz in fact is not a free-for-all and involves, as I claim, a number of previously prepared musical ideas, one might be led to believe that notation is the crucial difference between composition and improvisation. However, as Jeremy Begbie points out, “it seems odd to claim that composition only happens when musicians write music down.” Here we might also mention that it is not uncommon for jazz musicians use written arrangements for both large and small ensembles. In light of this apparent “dead end,” Begbie offers the following as a possible way to differentiate composition and improvisation,
A more promising way forward is to take composition to refer to all the activity which precedes the sounding of the entire piece of music, everything which is involved in conceiving and organizing the parts or elements which make up the pattern or design or the musical whole: and improvisation to mean the concurrent conception and performance of a piece of music, which is complete when the sound finishes (italics added).
With the above conception, composition entails all the musical activity that takes places prior to the performance of the piece as a whole, whereas improvisation consists in the simultaneity of conceiving and performing a musical idea. In other words, the act of improvisation emphasizes experiencing the “present,” i.e., rather than highlighting product or result, the accent is on process and activity, as “conception and performance are interwoven to a very high degree.” With what Begbie has just said in mind, perhaps we could say that the improvisation that emerges in the musical genre of jazz is a kind of present, spontaneous, music-making activity that purposely and re-creatively utilizes prepared and hence thoroughly familiar musical ideas. Yet, we should also highlight the following with regard to classical composition, which hopefully only complicates rather than contradicts Begbie’s way of distinguishing improvisation and composition. Despite the fact that a kind of mythology portraying composition as a flash of instantaneous inspiration coupled with the Kantian idea of a creative genius tends to dominate our conception of the way in which a musical composition comes into existence, I agree with Benson that composers themselves actually engage in a great deal of improvisation. As Benson observes, “composers are more accurately described as improvisers, for composition essentially involves a kind of improvisation on the already existing rules and limits in such a way that what emerges is the result of both respecting those rules and altering them.” In the end, given the mutual interplay between composition and improvisation, perhaps it is better to think of improvisation in terms of a continuum that ranges over both jazz and classical music, and that the structures of each allow for a greater or lesser degree of improvisation to manifest in the actual performance of the music.
 The same however could be said of some expressions of twentieth and twenty-first century classical music. Though I have stated this in an either/or way, to be sure there are other roles that a dominant 7th chord can play. Begbie, Theology, Music and Time, p. 183. Also, would writing down an improvised solo then make it a composition?
 Ibid., p. 183.
 Begbie, Theology, Music and Time, p. 184.
 Benson, Improvisation of Musical Dialogue, p. 133.