Dark Entries and Honey Soundsystem Records have teamed up again to release another volume of gay porn soundtracks by San Francisco-based musician and producer, Patrick Cowley. Perhaps one of the most revolutionary and influential people in the cannon of disco music, Cowley created his own brand of Hi-NRG dance music coined "The San Francisco Sound."

Muscle Up is a collection of Cowley's instrumental songs recorded between 1973 and 1980 found in the Fox Studio vaults. This compilation also includes bonus compositions found in the basement of Megatone Records owner John Hedges and the attic of former bandmate Maurice Tani. Influenced by Tomita, Wendy Carlos, and Giorgio Moroder, Patrick crafted an electronic sound from his collection of synthesizers, percussion, modified guitars, and hand-built equipment. The listener enters a world of forbidden vices evocative of Patrick's time spent in the bathhouses of San Francisco. The songs on Muscle Up are divided into four sides, each showcasing a different facet of Cowley's work. Side one opens with an ambient journey through the Amazon. Tension builds on side two, with the instrumental demo version of the slow-chugging masterpiece "I Need Somebody To Love Tonight". On sides three and four things go interstellar with ecstatic space-funk and galactic workouts.

The tapes were restored and transferred using the same speed and pitch settings, then remastered for vinyl by George Horn at Fantasy Studios in Berkeley, CA. The vinyl comes housed in a extra wide spine jacket and giant fold-out poster featuring a handmade collage using photography and xerox graphics of classic gay porn imagery from the Fox Studio vaults by Berlin-based artist Gwenael Rattke. Each double album also contains a 8x11 glossy promotional "Muscle Up" replica poster with original VHS artwork plus an essay from Maurice Tani.