A few days ago I checked out a CD of music by Lou Harrison. Several works use and instrument called a tack piano. Does anybody know what this is? A web search yielded several more references to Harrison as well as a few to Frank Zappa, Tom Petty, and others--no explanations/pictures of the instrument itself. Aaron J. Rabushka [log in to unmask] http://www.cowtown.net/users/arabushk/