In Guitar Hero he appears when playing Frankenstein by The Edgar Winter Group (as it is the only instrumental song in the game except for Trippolette). In Guitar Hero II he appears when you play Jessica by The Allman Brothers Band, Misirlou by Dick Dale, YYZ by Rush and Jordan by Buckethead (In Jordan he replaces the Bassist).
The Keyboardist is a long-haired, blond, overweight, mustachioed man. In the first game, he wears a white sleeveless T-shirt with a black "Death By Metal" design, blue jeans, white sneakers and black wristbands. In the second game, the only change to his appearance is his shirt, as he now wears a black T-shirt with a tuxedo design on it.
In the Guitar Hero documentary, they say his name is Larry, and that "he is only in the band because he is the drummer's cousin." It was also mentioned in the documentary that they would have made him an unlockable character if time had allowed it. He has not appeared in future games as an unlockable character.