A new kind of quarter-tone piano was recently developed in Finland. The idea was to create a full-range keyboard instrument that enables the player to perform melodic lines and chords that include quarter-tone intervals.

The new kind of keyboard was designed by composer Sampo Haapamäki and pianist Elisa Järvi.

The development of the new quarter-tone piano has been a multistage process. First, a single-octave prototype was built by piano tuner Matti Kyllönen in 2011. Finnish carpenter Otso Haapamäki created the prototype for a full-sized keyboard, and, in 2015, he built a keyboard for the Sibelius Academy.

Initially, the aim was to build an acoustic instrument. Unfortunately, this was not possible, as there are no longer any working piano factories in Finland. Reaching an acoustic quarter-tone piano is still in progress.

The present instrument is an extended version of the traditional piano, consisting of the new quarter-tone piano keyboard with midi-output. There is an optical sensor under every key that reacts to the pianist’s touch and transfers information regarding pitch and dynamic level to the computer. Music technologist Libero Mureddu created the necessary software patches and worked as a consultant during the project. The keyboard is then connected to two Disklavier pianos which are tuned one quarter-tone apart, and the performer “remote controls” the acoustic pianos from the quarter-tone keyboard. In this way, the sound is produced acoustically, although there is a time delay of approximately 200–400ms depending on the piano model. This is naturally a challenge for the performer, who has to anticipate every beat when performing together with other musicians.

The keyboard can also be connected to loudspeakers and used as an e-piano.

This website introduces some historical aspects of a quarter-tone piano, the need for the new instrument and the ideas behind the new quarter-tone keyboard design.