Originally Posted by garymosse
Actually, all keys are playable on the harpsichord -- its just that some may require a bit of retuning. If you are playing a piece in B major, you just tune the harpsichord so that it sounds good in B major. If you have several pieces to play, for example in B, A, E, and D, you pick a compromise, say optimizing the A and trusting the remaining keys to be close enough. If you have pieces in B, A, Eb, and Bb, you put them in different halves of the program, and use the intermission to retune.
If your piece modulates from, say, A to Eb, you may experience some discord...