Tack piano

The tack piano is a permanently altered version of an ordinary piano, in which tacks or nails are placed on the hammers of the instrument at the point where the hammers hit the strings, giving the instrument a tinny, more percussive sound. See prepared piano.

Perhaps this preparation attempts to emulate the sound of a poorly maintained piano: as the felt hammers age and compact through use they become hard and cause the piano to yield a similar sound. A piano tuner will use a tool consisting of a number of fine pins to open and loosen the striking surface of the hammers, called voicing, a precision job calling for a good ear and lots of experience.

The use of tacks on a piano is always discouraged, as they will usually be ejected from the hammers and can then become lodged in other parts of the mechanism. If the jammed mechanism is then forced by hitting the keys parts of the action may be broken. But most importantly, the holes created in the hammers by the tacks act like a poor job of voicing, and may permanently reduce the sound of the piano to dark mush once the tacks are removed.

A safer alternative to real tacks is a curtain of felt hanging between the hammers and strings. The felt is slitted on the edge, and paper fasteners or paper clips attached. The device can be purchased commercially or built by hand, but ultimately causes the piano hammers to be worn away from repeated impacts with hard metal.

Canadian pianist Glenn Gould experimented with a tack piano, which he called a "harpsipiano" (a portmanteau of "harpsichord" and "piano"). It was intended to imitate the sound of the harpsichord, and he used it in a recording of a Bach cantata.

In popular music, Elvis Costello used a tack piano on two songs on the album Mighty Like a Rose: "The Other Side of Summer" and "So Like Candy," which was co-written with Sir Paul McCartney. The German pianist Fritz Schulz-Reichel had considerable success c. 1955-57 on the hit parade with his tack piano recordings, released under the name "Schräger Otto" ("Crazy Otto" or "Slanted Otto" in German). During the craze, ragtime and blues pianist Johnny Maddox also recorded The Crazy Otto Medley with a tack piano, starting a "honky-tonk piano" fad. Both purportedly used thumbtacks in the felt hammers.