A musical keyboard interface capable of controlling either a string instrument or synthesizer controller includes a small, consistent keyboard interface that moves with each hand along one or both edges of a stationary ruler. The ruler segments measure the static location of each note in chromatic order. The keys are oriented in length perpendicular to the length of the ruler and each key is as wide as each ruler segment. As the keyboard moves along the ruler and its keys realign with new ruler segments, the keys become able to articulate the notes indicated by their position. The transformation is gradual, smoothly sliding notes and chords in varying magnitudes and directions simultaneously.

A musical keyboard interface capable of controlling either a string instrument or synthesizer controller includes a small, consistent keyboard interface that moves with each hand along one or both edges of a stationary ruler. The ruler segments measure the static location of each note in chromatic order. The keys are oriented in length perpendicular to the length of the ruler and each key is as wide as each ruler segment. As the keyboard moves along the ruler and its keys realign with new ruler segments, the keys become able to articulate the notes indicated by their position. The transformation is gradual, smoothly sliding notes and chords in varying magnitudes and directions simultaneously.

A hybrid acoustic piano, specifically a piano the wires whereof are struck, of the type including a grouped wires, where of each group of three or of four wires associated with a key, one of these is tuned at a pitch different from the other two or three, which are tuned identically; and where the mechanism is such that when the pedal is in a resting state, that is, without depressing the pedal, on pressing the keys, the hammers strike at least two wires of the three or of the four wires of each group with the same tuning, and when the pedal is depressed, the mechanism displaces the hammers to the right and, on pressing the keys, three wires are struck, one of which is the wire tuned at a different pitch from the others.

A hybrid acoustic piano, specifically a piano the wires whereof are struck, of the type including a grouped wires, where of each group of three or of four wires associated with a key, one of these is tuned at a pitch different from the other two or three, which are tuned identically; and where the mechanism is such that when the pedal is in a resting state, that is, without depressing the pedal, on pressing the keys, the hammers strike at least two wires of the three or of the four wires of each group with the same tuning, and when the pedal is depressed, the mechanism displaces the hammers to the right and, on pressing the keys, three wires are struck, one of which is the wire tuned at a different pitch from the others.