The only reason that I would recommend AP Bio for a person who wants to go into econ is that AP Bio is useful general information that can help you to understand, just a little, the basis of medical care in your future.
In your case, IF you are a truly talented accompanist, who can accompany college choruses or be the rehearsal pianist for musicals, this is something that can help you to get into colleges that don’t have associated conservatories or schools of music, since most colleges like to have a vibrant on-campus student performing arts scene, so capable accompanists are in demand. This might be the thing that moves you past the “good enough to accept, but so are 10,000 others, so put em on the wait list” pile into the “she has a talent we need, in addition to great qualifications” accept pile. I’m not saying that will happen at MIT, but it might happen at other schools, and meanwhile, having taken AP Bio instead of chorus won’t make enough difference at MIT or anywhere else, either.
So I’d say, do what you love (chorus) and try to parlay your accompanist abilities into the desired EC that gets you into a highly selective school that you want.