Harpsichord after Ioannes Ruckers 1638, two-pitch-instrument, double-manual

The two-manual harpsichords of the Ruckers family offered, as it were, two different-sounding instruments in one case. The manuals were typically offset by a fourth. This meant that the lower manual sounded a fourth lower than the upper manual, which sounded at 'standard' pitch. Of course, it was not possible to couple the two manuals in this arrangement - rather, one manual had to be switched off in order to play the other. Many of today's most famous musicians had such an instrument at their disposal.