Boulder-based outfit Eminence Ensemble took their act to Michigan’s Electric Forest last weekend for the first of two waves of the festival, and the group welcomed to the stage keyboardist Joel Cummins, from their brothers-in-prog-jamming Umphrey’s McGee.

Cummins came up to lend his keys skills to Eminence Ensemble’s “Hacer Sex,” a slow-burning jam from their 2014 album Mouse Hunt. Watch a video of the collaboration above.

Eminence Ensemble will also be playing after parties at Morrison, CO’s Cliff House Lodge this weekend during Umphrey’s McGees run at nearby Red Rocks Amphitheatre.

NOTE: An earlier publishing of this article incorrectly named the band as Emancipator Ensemble