They were both regulars in the New York gay clubs that were disco’s natural habitat. But you get the feeling that most of the rock bands who went disco had something rather basic and craven on their minds. An excerpt from the Guardian
There was always the chance of some short-term commercial gain but the odds were stacked against you: the back catalogues of umpteen 70s artists are flecked with ignored attempts to cash in on the 
success of Saturday Night Fever, remembered largely by fans as catastrophic career aberrations. Even if you did get a hit out of it, your success would almost invariably be accompanied by mockery or even anger. “Rarely has anyone betrayed his talent so completely,” thundered Rolling Stone, perhaps a trifle melodramatically, of Rod Stewart not long after Da Ya Think I’m Sexy? went to No 1.
The result was that a vast number of wildly improbable artists gave disco a try, with some fairly mind-boggling results. The Grateful Dead went disco on 1978’s Shakedown Street. So did the Kinks, whose single (Wish I Could Fly Like) Superman sounds oddly not unlike Blur’s Girls and Boys. So did Kiss, apparently much against the better judgment of bassist Gene Simmons: “I hate playing that song,” he said of 1979’s I Was Made for Lovin’ You. “Stadiums full of people jump up and down like biblical locusts … kill me now.”
There were certainly inspired rock/disco crossovers: the Rolling Stones’ peerless Miss You, ELO’s brilliant Shine a Little Love and Last Train to London, and Blondie’s Heart of Glass. But there were also scores of records that, in retrospect, beggar belief. Who wouldn’t want to hear a disco version of Gershwin’s Rhapsody in Blue by cape-sporting prog rock keyboard wizard Rick Wakeman? Who wouldn’t find the idea of a disco album by Ringo Starr (1977’s Ringo the 4th, featuring the unspeakable, castanet-heavy Tango All Night) anything other than delightful?
Anyone with a brain views it the way Brian Eno did at the time (“I have heard the sound of the future,” he breathlessly told David Bowie during the sessions for “Heroes”, before playing Donna Summer’s I Feel Love)
