A form of jack used on two- or three-manual harpsichords that do not employ a manual coupler. The dogleg jack is not bent, as its English name implies; but its lower third is partly cut away to form a step. This step rests on the end of an upper manual key while the uncut portion of the jack reaches down to rest on the corresponding key of the lower manual (see Harpsichord, fig.17). Consequently, when the dogleg register is engaged, it automatically sounds from both manuals. (This makes it impossible to play a Pièce croisée unless the upper manual is provided with a second independent unison register of its own in addition to the dogleg.) Although most harpsichords having dogleg jacks (in particular those of the 18th-century English and Netherlandish schools), do not have sliding keyboards, German harpsichords occasionally often employ a short dogleg jack and a sliding lower manual whose keys are fitted with small padded blocks. When the lower manual is pushed inwards, these blocks are positioned beneath the uncut portion of the jacks, permitting them to be activated from the lower manual as well as from the upper. In this way, the upper manual jacks are coupled to the lower manual without actual coupling of the manuals themselves. When the lower manual is pulled outward, the blocks pass in front of the uncut portion of the jacks and the jacks are activated only by the upper manual, thus making possible the performance of pièces croisées.
EDWIN M. RIPIN