I recently found the Journal of Music Theory Pedagogy and have been reading through the content. I wanted to share Keith Salley's 2007 article, Beyond Chord-Scale Theory - Realizing a Species Approach to Jazz Improvisation, because it articulates many of the points that I like to make about the chord-scale approach, but with better language than I could ever muster. Salley's main beef is that chord-scale theorists assume every chord has a corresponding scale, and vice-versa; chords and chord-scales are interchangeable; and all tones in a chord-scale possess the same level of structural importance (except when they don't, i.e. the major seventh in the bebop scale, "avoid" notes). Because of this, connections between chords (harmonic progression, voice leading, counterpoint) are ignored despite evidence that multiple structural levels do exist in jazz music (particularly in bebop). Salley produces numerous examples from the repertory that fly in the face of chord-scale theory and confirm the presence of structural levels in jazz improvisation. Chord-scale theory emphasizes pitches as they relate to an immediate harmony. This is contrasted by "target contexts," which involve tones that may or may not be related to the immediate harmony, but which have a contrapuntal relationship to a chord tone in a harmony that comes later. ========================== The second part of Salley's article advocates for a species model of improvisation pedagogy that acknowledges functional hierarchy in chord progressions and prioritizes voice leading awareness and motion between structural and non-structural tones. In all cases, a chord's "core arpeggio" (the root, 3rd, 5th, and 7th of a chord) provides structural tones, and extensions are view as displacements of those structural tones (and are dissonant). I won't go into it too much here, as it is very detailed and this post is already long enough, but this the spiel for dissonance treatment in his species approach for improvisation: The species are 1:1 (one note per chord) 2:1 (two notes per chord) where one is a member of the core arpeggio 4:1 with conjunct motion (with an occasional third), including enclosure figures like those in his Charlie Parker examples 4:1 with compound melody (meaning wide leaps are allowed, as long as they are governed by voice leading) 8:1, permitting leaps of a third between tones outside of the core arpeggio 8:1, compound melody (as per fourth species), with some stuff to emphasize enclosure figures Salley mentions that he has not accounted for suspensions and retardations in this species approach, and that the inclusion of such figures would require a more complicated species network. Personally, I feel that he should have at least given the first steps for suspension and retardation, as his argument (at least in part) is that chord-scale theory does not account for such figures in a satisfactory way and the basic concept has received extensive treatment in similar systems for hundreds of years now. I'm not sure whether anyone has tested out this system with real live students, but it does seem more structured than saying "here's a few scales, knock yourself out." ========================== Coming at this as an outsider, I appreciate this author's observations. Truth be told, jazz is not an area that interests me much. However, chord-scale theory leaks over into rock and metal training, so I am compelled to examine its claims and methodology and voice concerns over what I perceive as inconsistencies and inadequacies in the system. I don't think chord-scale theory describes what is happening in jazz music or any other music, and I suspect there is more at work in the intuitions of even the staunchest and most seasoned chord-scale adherent than the system accounts for. I am not a jazz player though, so who can tell. On the other hand, if you tell me you're going to the market to pick up half a dozen apples and you come back with a watermelon, I am going to suspect that what you say is not necessarily commensurate with what you do. When I consistently hear tonal resolutions in some music, you're going to have to try pretty hard to convince me that all tones are created equal in that music and voice leading is not a concern. Of course, I'd love for someone to change my mind.