Jacob Collier working out an arrangement of "Twinkle, Twinkle, Little Star"

This is a long video, almost three and a half hours, but it's also fascinating on three counts: 1) you see a skilled musician tinker around, refining an arrangement, 2) you get insight into Collier's harmonic imagination, and 3) in particular, you get to hear his use of microtones. Bonus: Listen to Collier's bass lines.