I was going to write something snarky about Tim Page, but I won’t. The Spoleto overview critic for the Post and Courier was in the audience tonight at a recital by avant-garde percussionist Gerry Hemingway. The concert started a little after 6 o’clock. Page was out of there by 6:17 p.m.

Perhaps he had another appointment. I don’t know. But his early departure has precedent. He admitted to leaving the American premiere of Monkey: Journey to the West, Spoleto’s buzz-worthy production costing $1.3 million, after 40 minutes, before the story turns to a search for redemption and enlightenment.

Though I do think a critic should give due diligence before leveling an opinion, perhaps Page is right. Why stay if you don’t like something? Why give your attention and time to a performer who is not reciprocating in kind, when a performer is self-indulgent, entitled, or even oblivious to the presence of an audience?

I’m not describing Hemingway. In fact, he’s a nice guy. I met him. He’s smart and earnest and devoted to the adventurous spirit of the avant-garde. But he’s no showman. His recital made that very clear. His powers of observation were such that he began giving an encore as throngs of people were heading for the exit.

I can only guess that Hemingway’s performance tonight was based on some kind of concept, but if you didn’t know what the concept was, you were screwed. It was a concatenation of imaginative sounds. Hemingway performed solo to a recording of sound effects — snaps and crackles and pops similar to the sounds you’d find in any urban landscape. For a long time, the performance had no discernible beat, but eventually there was a pulse. Then it was gone again.

The history of the avant-garde is grounded in the urge to challenge. It didn’t matter what you were rebelling against just as long as there was something to rebel against. This mode of thinking naturally emphasized the value of the art and de-emphasized the value of the audience’s experience. Composers had become the enlightened sages, the audience sanctified disciples following in their wake.

Or something. Anyway, if you liked something, the composer was doing something wrong. During the peak of the avant-garde — during the careers of John Cage, Morton Feldman, Milton Babbitt — there was no concern about the audience. Audiences had always been there and would always be there, except when they weren’t anymore. It’s remarkable to imagine composers wondering why no one’s paying attention to them while at the same time their work’s value is measured by how much they can piss people off.

I don’t think Hemingway was trying to piss anyone off, but his recital is of that tradition. Perhaps he was trying to liberate the drummer from the tyranny of meter. Perhaps he was trying to get us to experience the sound from the inside out. Perhaps he was trying to simply demonstrate the possibilities of a virtuoso musician and his instruments. Maybe it was parody of an audience’s rhythmic expectations.

Whatever the case, Hemingway was seriously losing his audience. People were looking around, checking their watches. The woman in front of us took her boredom as an opportunity to brush her hair. I checked the time three different times: once when Tim Page left, again at 6:37 and then again at 6:49 p.m. Many people just left, which irritated me at first. Then I got to thinking.

If the tradition of the avant-garde assumes the participation of the audience, or even goes out of its way to provoke the audience, then what are the obligations of that audience? Naturally, people want to be polite. They also want to get their money’s worth. Beyond that, however, what are your obligations as a ticket-holder if the musician has abandoned what used to be considered his or her obligations: to entertain you, to engage you, to take you someplace strange and exciting.

I’m beginning to think: Not much. Spoleto audiences typically want to appear refined. But they might rediscover the value of being honest, too, and just walking out if something is not to their liking. It’ll be good for audiences, good for the festival, good for composers, and good for the art.