Of Montreal frontman Kevin Barnes duetted with his fans Solange ("Sleep in the Park") and Janelle Monáe ("Make the Bus") before their mainstream breakthroughs. And the band have assumed so many guises, they've left plenty of unconventional indie threads for other artists to pick up and run with, from Foxygen's louche glamour ("San Francisco") to Grimes' everything-at-once pop ("California”).