Maybe someone could tell you where the site is on here for the keys. You play by ear and my nephew does to and he has this problem..he never could tell me what key he was playing in. I learn to read sheet music and i learn sharps and flats of how many flats was on key signatures to determine what key I was in because I didnt have a good ear. If you are playing a song. For instance, if you are playing 3 flats , the key would be Eb, 4 flats, would be Ab, now, 5 sharps would be B major. This may be diffucult for you at first. Someone would say, you could learn this another way thur music theory, and i am not good with the theroy yet. Now, even when you play by ear, and learn all the Keys, how many sharps and flats, the song especially choirs songs do alot of key modulation{key changes} and chord progressions and you don't change keys with some songs, they use major and minor chords, this is why gospel comptempory songs {church songs} I think are the most difficult songs to play. Hope this helps a little. Be bless.