Every article tagged improvisation.
Guest author Brett Stine on writing with 8- and 9-note non-diatonic scales: using the diminished scale and Messiaen's third and fourth modes as compositional tools rather than just improvisation scales.
The five additional scales from Allan Holdsworth's 1993 book 'Just for the Curious', with his own symbols, the notes and the interval formulas for each.
Allan Holdsworth's own list of his most usable scales, from the 1992 REH video: the formulas, his personal symbols, and the triads, seventh chords and modes contained in each.