Grand Pianola Music does manage a level of banality that I find somehow impressive.
I obviously favor Adams' music more in general but I agree with that comment. And Wikipedia reports on its reception:
Grand Pianola Music was actually booed by a significant proportion of the audience at its premiere. According to the composer,"True, it was a very shaky performance, and the piece came at the end of a long series of concerts, many of which featured serialist works from the Columbia Princeton school....Grand Pianola Music must have seemed like a smirking truant with a dirty face, in need of a severe spanking". Despite the reaction, Adams maintains that the piece was not intended to 'thumb its nose' at the rest of the 'high art' pieces being performed at the event. The composer admits to be alarmed by the severity of its reception. Retrospectively, Adams finds that he is "impressed by its boldness".