Thanks, Bill ... I just realized that I posted this entry in "Flying Fingers" and not "Prog Wednesdays" where it's supposed to be ... oooops!
In the cover notes of their second album (Acquiring the Taste) the band's brave aim was to "... expand the frontiers of contemporary popular music, at the risk of becoming very unpopular." On one of their albums (Free Hand) the liner notes name 47 different instruments played by the quintet, and most of them with remarkable skill. They spanned a 10-year career (1970 - 1980) and although they had a cult following, their oddities alienated them from most of main-stream music consumption.
During that decade, I asked friends if they'd heard of Gentle Giant, and I only recall one person saying they had! They did tour the US several times, but typically as lead in acts for bands like Sha Na Na, Jethro Tull, Yes, and even being oddly paired with Black Sabbath (whose fans booed GG off the stage!). I love their complexity, skill, and "odd-ness", which is (I guess) a part of being Chordie's Manic Musicologist.