Two informal recordings from Brad Lehman:
A Sarabande in A major by Buxtehude, played first in A major (three sharps) and then transposed to A-flat major (four flats).
In his own words,
Informal rehearsal at home January 2005, demonstrating the tuning from Lehman’s research on the Well-Tempered Clavier [... and the] differences of expressive character within this unequal tuning.
The harpsichord here is in Flemish style, and was built by Anne Acker. There is only one set of strings at “8-foot” pitch, but the tuning lends such different tone to different keys (with sharps vs flats) that it sounds almost like a change of instrument.
Additional classical music videos are on Brad Lehman’s YouTube page.May 11, 2007 | In Video