Originally Posted by boo boo

Technically so is the guitar.

Piano was featured prominately in a lot of early rock n roll. A lot of Rolling Stones songs have piano too.

Hell, even Black Sabbath have piano songs. Not all rock music is "rock n roll" though, some forms of rock do have classical influences, there's nothing wrong with that, rock music is a lot broader than just rock n roll, hard rock and songs about bum sex.

Billy Joel might be a piano guy, but what he plays is still very rock n roll influenced, so I wouldn't say Collective Soul rock harder just because they use guitars.