movie's fatal flaw
There's one thing that kept this movie from being so much better than it actually was, and it's that Paul Simon took on one job too many. He wrote the screenplay and the music -- but he should never have acted.
Maybe all his appearances on Saturday Night Live convinced him he was an actor -- he isn't. His delivery is wooden (especially compared with the other musicians, like Steve Gadd and Richard Tee, who are much more natural). And he's just not a very charismatic presence.