This is probably a pretty accurate re-enactment of his reaction.

Comedian Bill Burr is, among many other things, the host of the very popular Monday Morning Podcast. In this week's episode (at bottom), Burr went into a rant about raves. Specifically, he ranted about how terrible electronic dance music (EDM) is. Referring to it as "that DJ music," he then started doing an annoying hum and predicted that a club DJ would be able to turn it into a successful song. Well, one of his listeners, a Harvard-educated, world-touring DJ named Raffael De Luca, took him up on this challenge and made a head-bobbing club track that legitimately could be a hit song:

Sources: LaughSpin | Raffael De Luca | Bill Burr