A mid-1980s article in Musician magazine on how Roger Waters of Pink Floyd first built The Wall begins thusly:

Something snapped in Montreal. It was partly the strain of a long tour to a close-the accumulated jet lag, hotel food, pre- and post-show ennui and oppressive stadium squeeze of faceless but demanding flesh of the 1977 Animals tour...What's more, the very vocal majority of people in that black hole of steel and concrete were less concerned with what they had to play and say than with who they were. 'They" were Pink Floyd and that was enough.

Roger Waters spit on a kid in the front rows that night. Pink Floyd's singer-bassist-songwriter also spent a lot of time afterward brooding on what his fame had done to him and how he came to such a scary pass. He later spent a lot of time writing it all down in a series of brutally confessional, emotionally graphic songs that eventually became Pink Floyd's multi-platinum 1979 seller The Wall.

Shortly thereafter, the movie version of The Wall would star Bob Geldof as Waters-stand-in "Pink", a few years before Geldof would organize Live-Aid, inadvertently prop-up a murderous Ethopian dictator, and become knighted in the process.

...Only to come full circle:

U2 frontman BONO had to separate SIR BOB GELDOF from TONY BLAIR to prevent him from spitting at the British Prime Minister. The crusading rocker came to the rescue after Geldof's discussion with the UK leader became so heated, he feared a saliva shower was on the way. He says, "I had to call him off Mr Blair. Literally spittle coming out, invective coming out, and Tony reaching over to me saying, 'I believe you've a greatest hits coming,' just to get a break from Geldof. "I have seen Geldof try to bite prime ministers. I accept the rules of ultimate fighting, which are: you can't poke someone in the eye or bite them, and Bob doesn't."

Well, at least he didn't shout, "One Of These Days, I'm Going To Cut You Into Little Pieces!"