A long-time multi-instrumentalist, Groffman has as a pianist participated in premieres of works by Alexandra Vrebalov, Sky Macklay, Daniela Candillari, Stephen Gorbos, Lawrence Kramer, David Werfelman, and Gabriel Lubell, among others. He has appeared in recital alongside Lucy Dhegrae, Kelvin Chan, Danielle Messina, Suna Avci-Gunther, Thomas Gunther, Meghan Dewald, and Nicholas Finch.

Drawing on a background as a performer of rock, jazz, and classical traditions, Groffman also sings and plays the guitar, bass, drum set, trombone, and (every so often) the banjo. He is active as a performer and orchestrator for silent film; films on which he has worked have been performed in the United States, France, and Italy.

As a performer and organizer, Groffman champions contemporary music through his work as founding artistic director of One Quiet Plunge, a group devoted to the promotion and performance of new music in the Hudson Valley; since 2014, the group has staged concerts and multimedia presentations at locations around the Valley, including multiple commissions of new works by emerging area composers.