<Li> Starcastle: A progressive band from the US similar to Yes </Li> <Li> Stackridge: An English band who combine progressive rock with upbeat, catchy pop, psychedelic, and folk music, and have been described as the precursors of Britpop . </Li> <Li> Stormy Six: A politically active 1970s Italian band who later aligned with RIO </Li> <Li> Strawbs: British 1970s symphonic prog band with strong folk roots Rick Wakeman on keys </Li>

Prog rock group of the 70s three letters