First, I certainly understand that drunkenness impairs judgment and makes people less discriminating in how they might throw around their money. But that's not the mystery. If you are right that people's perceptions of strippers are analogous to their perceptions of musicians or bands, it only underscores the thing I find bizarre about people's perceptions of musicians. Hear me out here....
With a stripper, it is obvious that she has "what you want." Her performance is designed to demonstrate that she has a beautiful body that you want to see (or perhaps something more, but let's keep it family-friendly here.) As the client, you perceive her almost-taking-off-her-clothes as a tease: She obviously COULD take off all her clothes at any minute to give you what you want, and the only thing stopping her is waiting for you to dole out the cash to make it worth her while.
Now if this is what is going on with the person who expects (and is willing to pay for) the band to play "Free Bird," something is very weird about this. It suggests that although the band has been playing jazz standards all night, the person perceives this as merely a "tease" that demonstrates that if they wanted to, they could play what he/she really wants to hear (say, "Free Bird") -- and that the only thing standing in the way is adequate motivation (e.g., a $140 tip).
Actually, I think this might actually be right. But if it is, it underscores the idea that people have perceptions/beliefs about musicians that are really bizarre: i.e. that if they can play jazz standards, for example, then they surely are able to play any song that one might name at the drop of a hat -- and they are withholding "Free Bird" only because no one has tipped them enough yet. And that's my point. Do people really believe that if you are a musician/band, you not only know, but could play on request, any song in the universe? And again I repeat the challenge: In what other profession or domain of life that is perceived this way?