Scores
After briefly considering the relation between Western traditional notation and improvisation, this section focuses on alternative types of notation that emerged in the 20th century, in the form of lead sheets and indeterminate scores.
Western traditional notation
While the decline of improvisation in Western classical music can be attributed to various factors, as stated in the introduction chapter, it's undeniable that the evolution of notational practices plays a big role in this development. As notation evolved at the end of the 18th century, reaching new levels of specificity in regards to structural elements, standardized symbolism, metronome markings and improved copying, composers – with Beethoven at the forefront – could gradually exert more control of the performers and their readings. The score, effectively, became an authority that could stand on its own (Goehr, 1994). However, as stated earlier, even highly specified scores require a certain degree of improvisation, since there are always things that cannot be fully specified using Western traditional notation. In Cobussen's (2017) words, "it is the score that instigates improvising, improvising as reworking; the fundamental and inevitable shortcomings of the score compel a performer to make her own decisions" (p. 111).
Lead sheet notation
Just as the development of Western traditional notation is intrinsically linked to the evolution of Western classical music, the emergence of the lead sheet has a strong connection to the history of popular music and jazz. Developed from a need to catalogue popular tunes for radio broadcasting, the so-called Tune-Dex card was developed. The Tune-Dex card was a form of index card where one side contained a simple representation of the melody and chord changes taken from the refrain of a particular song (Kernfeld, 2006):
On the other side was printed out practical information related to publishing companies, available arrangements etc. These cards were ultimately used (illegally) as the basis for the first jazz fakebooks in the ”fakebooks” in the 1950s, and subsequent songbooks like the Real Book.
Whereas popular songs from the turn of the twentieth century were notated using conventional music notation – with one staff for the voice and two staves for the accompanying piano part – the lead sheet established itself as a single-staff approach to representing popular music, focusing on the melody and general harmonic progression. This way, the lead sheet encapsulates what Davies (2001) refers to as a thin work, in the sense that the level of specificity is low compared to a fully-notated composition, i.e. a thick work. ‘Thin’ or ‘thick’ here do not necessarily reflect the level of detail that the composer/songwriter intended, but how the song is represented in a notated form.
Seen from a performer perspective, the low specificity of the score means that the person interpreting the sheet needs to rely on his/her stylistic knowledge and improvisation skills for building the full arrangement, to ‘fill in the gaps’. Details that the performer need to supply involve accompaniment patterns, rhythmic character, dynamics, ways of interpreting melody and harmony – which are often presented in a more simplified or rudimentary form – and even the form of the arrangement, seen that it is typically not specified in the lead sheet. Seen this way, the lead sheet can be seen as an imperative to bring in improvisation on many different levels. This is also known as to ‘fake it’; hence the name fakebooks.
Chord symbols
One distinct feature of the lead sheet is its representation of harmony via the chord symbol, a system of notation based on tertian harmony, i.e., chords based on thirds. Here, chords are denoted based on their root note (e.g., 'C'), their chord quality (e.g., major or minor), their extensions (e.g. 9, 11), and alterations of certain intervals (e.g, b5, #9). For instance, a symbol such as Cm9(b5) reads as a minor chord, starting on the note C, where the fifth is flat – lowered a half-tone – and where there is an added (major) ninth as well as the (minor) seventh. Unless otherwise indicated, a seventh added to a triad is assumed to be minor, while extensions above the octave are assumed to be major (ninths and thirtheenths) or perfect (elevenths). A precursor to the chord symbol can be found in the fingering symbols that started appearing on song sheets in the 1920s, as a guide for ukulele players to create a basic chord accompaniment. These symbols first appeared as small boxes with diagrams showing where to place the fingers on the strings, and then, in the 1930s, with added chord names to facilitate for other chord instruments. Guitar diagrams eventually replaced these boxes, as the guitar gained more popularity as an accompanying instrument (Teriete, 2020). However, the use of symbols to indicate chords was not a new phenomenon in musical notation practices; an earlier precursor can be found in the ’figured bass’ of the Baroque period, where chords are symbolized by numbers above a written bassline that indicated the intervals that formed the chord. Considered one of the earliest ways to indicate chord-like labels, the figure bass resembles the chord symbol in that it is the abstract chord that is specified, rather than its exact voicing (Williams & Ledbetter, 2001).
Besides being intrinsically linked with the American songbook, the lead sheet also established itself as an integral part of jazz performance practice. One of the single biggest contributor, it can be argued, is the so-called Real Book. The Real Book – whose name is a pun alluding to the term fakebook – is a book that appeared in the 1970s containing a collection of lead sheets based on popular repertoire among jazz musicians at the time, transcribed in a way that reflected what musicians actually played on the recordings. Besides the expected repertoire from the so-called American songbook, there were also several compositions by young musicians that were emerging at the time, such as Pat Metheny, Carla Bley, and Steve Swallow. However, as the book was put together by students at the Berklee College of Music, it wasn't a priority to settle copyrights or pay royalties to the rights holders; the first versions of the book, thus – that are still in circulation – were sold illegaly (McCavana, 2021).
One of the criticisms of the lead sheet as presented in the Real Book – in relation to a jazz context – is that once a certain version of a tune becomes written down, it also sets a standard for how the tune will be performed from then on; same key, same set of chord changes, with the risk of stifling the creative freedom typically expected of jazz improvisers. This has even been likened to the effects of notation in classical music, and the consequences thereof. As Roman Mars puts it, ”when musicians play a version of 'Bye Bye Blackbird,' that sounds exactly as it appears in the Real Book, they’re acting more like classical musicians than jazz musicians” (Mars in McCavana, 2021). Another aspect, as expressed by trumpeter Nicholas Payton, is that reliance on lead sheets reduces a multi-dimensional art form into a ”manageable packet of digestible information”, without a way to convey its expression and way of thinking. Seeing jazz as a fundamentally Black cultural phenomenon that can’t be taken out of its historical context, Payton stresses the importance of immersing oneself in the culture of the music; learning directly from elders, in person, is a crucial part of what it means to really know the art form (Payton in McCavana, 2021).
Indeterminate scores
Indeterminate scores – also known as aleatoric scores – emerged as a notation form as a result of the expressive needs of composers in the 1950s, particularly by the group known as The New York School, consisting of the composers John Cage, Morton Feldman, Christian Wolff, and Earle Brown. While indeterminacy or aleatoric music can refer to the random or chance-based procedures that goes into the creation of a work – e.g., when a composer uses a random number generator to generate pitches or rhythms – the focus here is on indeterminacy as a property of the score itself, the musical notation. In this context, aspects of the score are intentionally left open-ended, offering performers a framework that can be interpreted in a variety of ways. This involves a deliberate ceding of control on the composer’s behalf – related to parameters such as pitch, rhythm, expression, and musical form – allowing performers to exercise greater freedom in shaping the music than when playing from traditional scores.
One common type of indeterminate notation is the so-called 'boxed notation'. The way it works is that the composer puts the necessary information for the performers in an improvisation box, such as a set of pitches or a rhythm. Attached to these boxes, the composer also gives instructions for how to treat this material, such as ”improvise on given pitches”. (Stone, 1980, p. 156)
Common variations are that the performer can deviate in tempo using the given material, change the order of the material – e.g., the order in a given set of pitches – or to interpret the material freely. For notating rhythms with indeterminate pitches, it’s common to use crossed noteheads or stems without noteheads (Gould, 2011):
Another type of indeterminacy is when the form structure of the piece is left to the discretion of the performer. This approach, often referred to as 'mobile form' can be found in pieces by Karlheinz Stockhausen from the 1950’s, such as his Klavierstück XI. It should be noted, though, that in this work it is only the order of the events that is left to the performer to decide; the musical content of the different passages are still written out with the a high degree of specificity.
Another type of indeterminacy can be found in Terry Riley's way of working with cells in In C (1964). In C is an early minimalist composition written for an unspecified number of performers. The work consists of 53 numbered musical phrases. Each performer can repeat any phrase any number of times before moving on to the next:
As Lars Bröndum (2018) points out, indeterminacy and improvisation have many common traits, such as an ”invitation to the unknown” and a focus on process rather than seeing music as something fixed and immutable. They are, however, not one and the same. With indeterminate scores, there’s a tangible risk that the idiosyncrasies of the score, with its special demands, come at the jeopardy of the spontaneous creativity from the performers’ side. This is addressed by James Grier:
Although they [indeterminate scores] allow the composer to explore new techniques and sounds, the study they require on the part of the performers challenges the quality of spontaneity they might be able to apply especially when the piece envisages improvisation, as in Stockhausen’s Plus Minus. And so composers always run the risk that by trying to impose yet more control on the performance, they might jeopardize that control through issues that arise in the notation. (Grier, 2021, p. 200)
As pianist Lisa Ullén explains it: ”as an improviser you are listening and performing, responding to the room, and the others who you play with and creating at same time together” (Ullén in Bröndum, 2018, p. 651). The collective listening and co-creation, thus, might not come into fruition to the same extent when there’s a detailed score present controlling the process. Another pitfall is expressed by another of Bröndum’s participants, saxophonist Per Gärdin: ”there is a wider range of interpretations, and if you get specific instructions how to do the interpretation contradicting your own impulses, you may feel that you are not more ‘individual’ than with a traditional score, maybe even less” (in Bröndum, 2018, p. 651).