Is it permissible to play the piano and join a musical band, given a talent for it, or is playing music unlawful, and how can this talent be utilized in another way if it is unlawful?

The piano, like other musical instruments, is forbidden to play and listen to. One must repent to Allah, get rid of it, and stop playing it permanently. This talent is a test from Allah. Whoever abandons something for the sake of Allah, Allah will compensate him with something better, and he will find other permissible talents.