Definition: A transposing keyboard is a manual that allows a performer to quickly change the home key of an instrument in one of the following ways:
- A second manual that is either permanently tuned a fourth interval above the main manual, or transposed with a hand stop; seen on early Flemish harpsichords before concert pitch became standard.
- A single manual instrument in which the action may be moved laterally, causing the hammers to strike different strings.*
- Some electric piano and MIDI controller keyboards can be transposed at the touch of a button.