Amazon.comThese two quartets should have been part of a set of six, as was Haydn's custom in writing string quartets, but as he hit 70, he developed what seems to have been a serious case of arteriosclerosis, and for the next seven years until his death he was unable to concentrate sufficiently to compose any new music. There's certainly no sign of any decline as far as these pieces are concerned: in fact, they are widely considered to be Haydn's greatest instrumental works in any medium. It's interesting the Prince Lobkowitz, who commissioned the works, was also the dedicatee of the first set of quartets by Haydn's cranky and difficult pupil, Beethoven. Magnificent music and performances. --David Hurwitz