I answered one advert because I liked the bands that they mentioned in the advert, met them in the pub and they seemed ok, so sorted out a rehearsal date. As it was an originals band, they didn't have anything in terms of songs/structures (which was a bit of a worry), so they gave me two song covers to learn, as apparently they played these all of the time.
I get there and the drummer doesn't know either of these "regularly played" songs. Also, it turned out that the singer/guitarist has only one song that he is working on, which I bluffed my way through, as he had nothing written down and nothing else.
I didn't go back - I would be stunned if it went anywhere.