Arturia KeyStep Pro Keyboard with Advanced Sequencer and Arpeggiator - Manual (Page 56)

The Trans/Clear Button
By holding down the Trans (Transpose) button and pressing a key on the keyboard, you
can transpose the running sequence to another key signature. The Transpose button is a
toggle button. Once you have applied a transposition to a sequence, the transpose button
will 'remember' that transpose action. If you press it once more, you return to the original
untransposed sequence. Thus you always have an untransposed and a transposed version
of the sequence at hand, and you can toggle between them!
Transposition is linked to the currently selected track. In a live situation, you can for example
transpose Track 1, then select Track 2 and apply a transposition there as well. Holding down
'Shift' and pressing Trans/Clear will clear all active transpositions simultaneously.
50 Arturia - User Manual Keystep Pro - KeyStep Pro Overview