I'm on a real Mothers of Invention kick lately, and nothing could be better than the quintessential 1968 lineup (Don Preston, Roy Estrada, Ian Underwood, Jimmy Carl Back, et al.) performing King Kong. What gene pool made these guys? Largely classically trained, oversexed, jaded intellectual too-cool-to-be-hippie motherfuckers - they simply do not make bands like this anymore. They inspired so many, and were narrowly rewarded for their efforts. Of course, Frank Zappa's post-Mothers career and all-too-short life is well documented, but it's the Mothers era that never ceases to amaze me.
Note Frank's comment at the top of this clip thanking the BBC for "allowing them to do things..." - the US hasn't changed that much, if at all; we still have the worst artist-censoring record this side of Iran.