The musical duo of Ron and Russell Mael had been doing Kinks or The Who style music throughout much of the early 70s, but by the mid 70s they were tired with that sound, felt that it was stale, and tried a "West Coast" sound. Several recordings with studio musicians were released which the band felt were "bereft of personality." Deciding to go a completely different direction, they teamed up with Giorgio Moroder to revamp their sound as among the earliest synthpop groups out there. Moroder was famous (at that point) for producing some Donna Summer disco, but honestly; late era disco (as well as it's descendents, italo-disco, Hi-NRG, Eurodance, etc.) and synthpop were quite often separated by a very thin and very blurry line. Moroder would also go on to define the sounds of Blondie, Irene Cara, and others, and worked with David Bowie, Japan, Melissa Manchester and more, managing to transfer his disco synthesizers into a synthpop sound while style remaining trademark Moroder. Depeche Mode, the Pet Shop Boys and New Order have all cited this transformed Sparks, specifically the album Number 1 in Heaven as hugely influential on their own sound.
A few years later, Sparks brought back some of their live instrumentation, although the keyboards remained important, when they had their bigger US exposure with the 1982 album Angst in My Pants, the title track of which appeared on the Valley Girl soundtrack as well. Sparks continued to experiment with a variety of different sounds between rock and roll, and even in the early 90s they sounded like the Pet Shop Boys with 1994's Gratuitous Sax and Senseless Violins.
Sparks were also infamous for their look and stage presence. Younger brother Russell was an animated, charismatic frontman, usually with very big hair, while songwriter and keyboardist Ron was famous for his Hitler stache (later to be replaced with a thin, Errol Flynn pencil moustache) and nearly motionless scowl on stage. Sparks also appeared on Saturday Night Live at this time, and characteristically, Russell is bouncing around rather hyperactive, and Ron is just standing their scowling at his keyboard, barely moving a few fingers to play.