The String Cheese Incident have shared a clip of their much talked-about collaboration with Billy Strings at this May’s DelFest.

Following a jam with legend Del McCoury among others, Strings’ sit-in came midway through the band’s second set, in the form of a rip-roaring Black Cloud.

Watch Strings and SCI’s Bill Nershi trade high-speed acoustic riffs on the 13+ minute jam below: