Warning: most of this is accidents, deaths and odd moments. For some reason, that is all I can remember today, so I hope that is relevant:
Well, you have the famous mudshark + groupie = stuff of legends story. Google that one yourself, I ain't telling.
Most of Almost Famous were based on real 70s bands, but in the film most of the accidents were toned down. Both the electrocution (Stone the Crows, fatal in real life, not in the film), the air plane trouble (Lynyrd Skynyrd lost three members to an air plane crash in '77) and although I know there are more situations taken from real life, it's been too long since I saw that film to remember more.
Airplanes are the source of a lot of trouble for musicians. So much so that you have a list over music fatalities here:
http://listverse.com/2008/01/09/top-10-musician-plane-crash-deaths/. The song "American Pie" by Don McLean is partially about the trio on number one in that list.
Legends amongst those working in the business are maybe not so funny, but I have been told about the legendary Van Halen rider of '82 so many times (sometimes with other famous bands of the time, sometimes with red m&ms instead of brown) that it's something I feel needs mentioning. Full story here:
http://www.thesmokinggun.com/backstage/hall-fame/van-halen-82 There are many legendary injuries, like the pyro blast James Hetfield got in the face in 92 that could have killed him or maimed him had it not been that his guitar was a solid body one. You also have the Great White, whos pyro set fire to a club and a hundred people died, including their own guitarist (
http://en.wikipedia.org/wiki/The_Station_nightclub_fire). NME had a list over several less serious injuries here:
http://www.nme.com/photos/rock-n-roll-injuries/124827/3/1.
You have the legendary Roger Waters spitting episode:
http://www.angelfire.com/va/battersea/spit.html And the time Leonard Cohen walked of the stage because he was "too depressed to play on". (Can't find anything about this, so that might just be a nasty rumour considering how Cohen is famous for being depressing.)
Anything Phil Spector (the man behind "the wall of sound") ever did, from threatening the Ramones at gunpoint, almost shooting John Lennon and threatening Leonard Cohen with a gun (“He put his arm around my shoulder, pressed the muzzle into my neck and said, ‘Leonard, I love you.’ At which point I said: ‘I hope you really do, Phil.’”) That man was mad as a hatter and probably made more to make famous artists pray than any priest. People even made a list:
http://oldies.about.com/od/oldieshistory/a/weirdspector.htm You have the disappearance of Richey Edwards from the British band Manic Street Preachers in 94. He left his passport, parked his car by a bridge and was never seen again. Most of the people who knew him have refused to believe that he killed himself, and his family told the press that they still believed he was alive when they declared him dead a few years ago, but needed to get the paperwork in order.
For the more gory you have both Ozzie Osborne's bat eating incident... and his dove eating incident.
Twisted Sister's speech in court to defend their songs from the censorship to come (explicit lyrics, parental warning) didn't help them win the case, but is pretty cool in its own right (calling Tipper Gore a pervert, amongst other things):
http://en.wikipedia.org/wiki/File:Dee_Snider_at_PMRC_Senate_Hearing.ogv /
http://www.joesapt.net/superlink/shrg99-529/p73.html And while we're in court, Judas Priest who had to defend themselves from the accusation that their music made children kill themselves:
http://www.bbc.co.uk/music/sevenages/events/heavy-metal/judas-priest-sub...