The Bad Boy Giles theme song was "Tales of Brave Ulysses" by Cream; that song was on the album Disraeli Gears, which came out in 1967. (I think Cream broke up in 1970, or thereabouts, and Eric Clapton went on to do a whole lot of drugs.) I would say that, unless Giles is younger than I think he is, he should be decidedly rock rather than punk. So, like, what, the Yardbirds had broken up by then; the Beatles (who were hopelessly straight for Giles's taste) were about to break up. The Who might be too earnest for him; Pink Floyd too moony; maybe Led Zep? Zoso came out in 1971.
I want to say, on no evidence at all, that punk didn't really get started until the second half of that decade. [edit: Huh. I am a good guesser.]
Pink Floyd too moony
Well, their early stuff was definitely not moony. More weird.
Iggy & the Stooges (as DavidS mentioned above) would be just about perfect.
I'm leaning towards Zeppelin, who performed at Wembley in '71. God bless the Internet.
King Crimson would fit the bill very well as an occult-themed rock band that was quite influential in London from the late sixties onward. The Court Of The Crimson King ('69) had some references to Chambers and was an iconic weirdo-rock album that impressed Pete Townshend.
Not Zeppelin. I would think that rebel Giles would have been philosophically opposed to Zeppelin. If you're looking for a specific EVENT that he would have killed to go to, rather than just a band that he would have liked to have seen, what about the infamous Ziggy Stardust and the Spiders from Mars (aka Bowie) concert in 1973, at the Hammersmith Odeon on July 3rd, 1973? You can read about it here, and, if I recall, there is some proof that Giles did like Bowie, yes? (FYI, legend has it that a member or members of the future Sex Pistols stole the P.A. system that was used at this concert. You could have Giles do it instead, if you wanted.)
ah, well, it's written. I'll just have to hope that the fic readers aren't musical philosophers.
Not Zeppelin. I would think that rebel Giles would have been philosophically opposed to Zeppelin.
Why do you think this, Gandalfe (just curious--I'm not writing anything).
Led Zeppelin were the band that the punks railed and rebelled against. They were the establishment, and nobody who was anti-establishment would be for them.
I'd say Iggy, Bowie, maybe Marc Bolan.
Yeah, but Giles also liked
Freebird.
eta...
I know that's not a Zep song. Freebird just indicates to me Giles probably wasn't as proto-punk as we'd think.