May 26 Miles Davis would have been 75. Around here, the radio stations have been airing tributes to him the last few days.

One particular program mentioned that Miles' significant contribution to music was that he shifted the musical focus of improvisations from those based on chords to those based on scales or modes.

To the ear the shift is noticeable and markedly pronounced...but perhaps some music theorists could expound on and explain the differences between solos built around chords and those built around scales, for our edification.

Thread drift, cross-threading, and any other comments, observations, or silly statements are welcome as well.

Thanks in advance.