Foundations Of Cognitive Science

Piano Camera

The piano camera (also known as the Iowa piano camera) is a device that is used to record the action of piano keys as a piece is played.  A detailed description of this device was provided by Seashore (1938/1967, pp. 233-237).  It involves photographic paper mounted in a mechanism above the hammers of a piano, to which balsa wood strips have been mounted.  A motor drives the paper forward at the rate of 12 centimeters per second.  A hole in the balsa wood permits light to pass through, but this light will only be detected by the photographic paper (via a lens) when the piano key has been depressed, raising the hammer.  As a result, the piano camera produces a piano-roll representation of whatever is being performed on its keys!  The piano camera has an extremely fine temporal resolution, in the range between 0.01 and 0.04 seconds.  Seashore illustrated the utility of the piano camera by using it to create two performance scores (i.e. piano-roll representations) of a piece, which each score produced by a different performer.  Seashore demonstrated how this approach could reveal different approaches to producing phrasings of the piece being studied (Chopin’s sixth nocturne).


  1. Seashore, C. E. (1938/1967). Psychology of Music. New York,: Dover Publications.

(Added November 2010)