I have musical ADD
That's a good thing to have. People ask me if I like a certain band or sound and I give them a number. They get all like 'is that how many points out of a hundred?' and I go: "No, that how many minutes I can stand it before I feel compelled to get up and put something different on."
Sometimes, like if I'm doing a show like I did a year ago or so, where the top 3 acts are Hatebreed, Trivium and Cannibal Corpse I have to try pretty hard not to really listen to anything before the band I really want to listen to comes on, on or I will be uselessly burning through my daily allotments of Metal. 45 minutes of that at 100+db is good by me, I don't need more than that in a day. (Cannibal Corpse for those of you who were wondering.)
There is stuff like classical string music - trios and quartets in particular - late 50s/early 60s jazz, Bob Dylan and live Dead/Garcia tapes that I have enough of a taste in the genre (or unfortunate events in the past) to let that music play for days and days and days and not think about changing it. But some stuff like Tuvan throat singing, a couple songs are cool, 20 minutes of it is pushing it, and more than that is officially irritating.
Hell, after 90 minutes (out of what I knew was a 3 hour show) of Paul McCartney I got up and left walked around the stadium, went to a market, and had a doughnut and tried to clear my head so I could come back and watch the last hour (which of course had all the best stuff in it.)