The function symbol notation is the least used notational system in jazz. As the namesuggests, this notation specifies the harmonic function of individual chords and evencomplete chord progressions. It has the potential of being useful to notate specificbehaviors of chords that may not—at least, not on the surface level—indicate that theybelong to a particular functional family of chords. As such, function symbols enable theperception of harmonic progressions from a more structural perspective. Function symbolsindicate neither the architecture nor the specific scale degrees of chords. This style ofnotation is more conceptual than it is representative of a specific surface event. The termssurface level and structural level are used to describe musical events and the degree oftheir importance. “Structural” events occur beneath the musical “surface” and areresponsible for the overall tonal, harmonic, and melodic forces controlling the piece.Function symbols use three labels: T for tonic-type chords, PD for predominant-typechords, and D for dominant-type chords.

Lead-sheet notation, also known as popular-music notation, is by far the most widespreadnotational convention used by jazz musicians. It comes in a variety of forms that arisefrom its murky origins and subsequent vague implementations. There are many alternatenotational systems in use, which for better or worse every jazz musician needs to getfamiliar with for purely practical, “bandstand” reasons. Here, we will only use chordsymbols that are commonly found in published and respected fake books. Lead-sheetnotation is very specific in showing what the chord is: it indicates the letter name, theexact number and types of extensions occurring within a chord, chordal inversions, orcomplex polychordal formations. A chord symbol, then, provides a quick insight into thechord’s pitch content. As such, it can be easily transmitted into a voicing that capturesthe essence of that symbol. The downside of this labeling is the lack of contextualconsiderations, especially in regard to the underlying tonality. As a tonally “uninterpreted”notation, we are not quite sure, for instance, how chords relate to one another, how theirbehavior conveys the underlying tonality, and what the overall tonal logic of differentchord successions may be.In this book, upper-case letter names will be used to indicate major-type chords. For minor-type chords a “min” extension following an upper-case letter name will be used. The lead-sheet symbols from Figure 3.6 also employ slash notation; this specifies a chord typewith the lowest sounding pitch separated by a diagonal slash. An upper-case letter nameto the right of the diagonal indicates the chordal root. The letter name to the left of thediagonal shows a specific chord type.

Figure 3.6 illustrates the structure of four triads and their inversions labeled with threesets of notational symbols: traditional lead-sheet notation above the staff, and Romannumerals and function symbols below the staff. Since we will use them interchangeablythroughout the book, let us make some general observations about their usefulness intheory and practice. Each of these notational conventions has unique advantages, but alsosome obvious shortcomings.