How many scales are there?
Now there’s a question. The authoritative answer is given by Nicholas Slonimsky, whose Thesaurus of Scales and Melodic Patterns (NY: Scribner, 1947) goes into this in encyclopaedic detail. John Coltrane is famously said to have absorbed just about all of the material in Slonimsky and to have been able to call on it at will while soloing. For mortals, and for the sake of practicality, Slonimsky isn’t to be recommended. Apart from the sheer volume of stuff in there, according to Slonimsky and others, a scale can include intervals wider than a major or minor second between adjacent elements (the harmonic minor scale is a familiar example). As a resource for voicing or improvising, such scales aren’t as practical as a sequence of seconds with no holes. Most of the trouble in jazz voicing and improvising comes from the information gap between chord symbols (usually built from thirds) and the parent “scale” (built from seconds). Out of interest, I worked out that, even if you limit the defin
