Philly-based Up the Chain are still on a high from the release of their latest EP, Windows Into Worlds, on April 21. Today (May 8), Diffuser is excited to team up with the indie rockers for an intimate, acoustic performance of the EP's lead single, "The Hardest Stone" -- check it out above.

Comprised of frontman Reed Kendall, bassist Noah Skaroff and drummer Kirby Sybert, Up the Chain have traveled the world, from their hometown of Philadelphia to a recent monthlong stint in Germany and Switzerland, opening for Leon Russell and 10,000 Maniacs.

As for “The Hardest Stone,” the acoustic rendition sounds a bit different than the final studio version -- though it has a special meaning for Kendall and his bandmates.

“We usually perform this song upbeat and electric, but it started as a very mellow, finger-picked acoustic tune," they explain. "The original demo, which we included on the EP, is just two acoustic guitars in a big empty room with high ceilings, tile floors and sliding glass doors. There were big natural reflections throughout. We have a real doneness for it as it was one of the first things we recorded at the empty beach house that eventually became our studio. This video is us recreating the original version of the song."

You can pick up Windows to Worlds here, and make sure to check out Up the Chain’s official website to stay current with everything happening in their world.