Contraption IPP 71512

From NetNewMusic Wiki

The Contraption IPP 71512 is a piano-altering machine built by Trimpin that automatically turns a grand piano into a prepared piano. The machine rests on the lidless frame of a grand piano and, triggered by computer commands, lowers golf tees, bronze discs, rubber wedges, and other sound-affecting objects onto the strings. In addition to allowing the use of both prepared and unprepared piano within a single performance, the Contraption's wheels can also rotate in contact with the strings, rubbing them for a continuous bowed-piano sound. One of Conlon Nancarrow's last works, titled Contraption No. 1 (1993), was written for the instrument.

In the instrument's title, IPP stands for "instant prepared piano," and 71512 refers arcanely to one of the instrument's earlier incarnations. See Trimpin.