At PianoEasy we’re interested in creativity – using your imagination to make something new. So were the inventors of these three unusual keyboards, but instead of using their imaginations to make new songs, they actually reinvented their instruments entirely.

  1. The Ocular Harpsichordtabula

Have you ever noticed the parallel between the seven colours of the rainbow and the seven notes on a piano? That connection was first made by Isaac Newton in 1704, and about twenty years later a French mathematician (Castel) designed a keyboard instrument which could play music for your eyes – each key, when pressed, would reveal a piece of coloured silk or glass lit from behind by candlelight.

Castel’s instrument could create rhythm and tone, but as Johann Gotleib Krüger pointed out another 20 years later, it didn’t really allow colours to come together as chords. Krüger proposed that each key should throw a circle of light onto the centre of a screen, so when you played a chord the colours would be superimposed on one another. To convey pitch, the lowest key would produce the largest circle of light and the circles would get progressively smaller as you worked your way up the keyboard – similar to a regular piano creating low pitches with long strings and high pitches with short strings.

  1. The Steam Organ

steam-organIn 1795, early in the Industrial Revolution, William Mason came across a description in a Latin text of an organ powered by steam. Since then historians have decided that he probably misunderstood (because there’s no evidence of a steam-powered organ in any other texts from the time), but Mason was quite taken with the idea and suggested that in the future a steam organ might be built into a steam boat and played when the engine was idle.

In 1838 a steam organ capable of playing just one octave of notes was built by the Reverend James Birkett to be played at the opening of a new railway.

This instrument has since evolved into the calliope, which is recognisable for the gaudy tunes that are usually played on it – and surprisingly enough it actually was built into a few American steam boats!

  1. The Cat Piano

Thankfully there’s no evidence that a real cat piano has ever been built – but strangely enough it appears in a fair amount of art and literature, from the book Musurgia Universalis in 1650 to the dark short film The Cat Piano in 2010.


The idea behind this instrument is that cats with different vocal pitches are arranged in cells where their tails are hit by the hammers of the piano – or in some versions, pricked by a pin. The cat piano can be seen in a wide variety of contexts in literature – it’s presented as a joke, as a satire of a cruel upper class, as a cure for a distracted mind, and in one very early text, as an instrument that witches play.

A similar principle (using living things to make music) is behind other fictional instruments such as the Piganino, the Mouse Piano and the Torturetron; but these are all more recent and have only ever appeared in a comic context.

Clearly the keyboard has been the inspiration for some very interesting instrument designs over the years. Creative minds throughout history have wondered about the possibilities of keyboards connected to light, steam, or live animals; but here at PianoEasy we’re perfectly happy to keep ours attached to an ordinary piano!

– Blog by PianoEasy student extraordinaire Anastasia Beasley

Many thanks to the Museum of Imaginary Instruments for making this information available under a creative commons license.