Pat O'Brien's is GREAT!
My wife and I went there one night and about 4pm they had 2 "senior" folk playing piano, but they were good. At 6 pm they changed to 2 middle aged guys who were even better. At 8 pm they changed again to guy (25ish) and a girl (25ish) who were great! We ended up staying from 4-10pm and had a wonderful time. Good food as well.