But there have been exceptions, most notably Mr. Menuhin, who in his late teens became the first violinist to record all six of the unaccompanied works.

The contributions of Mr. Schulte, the violinist, included two intensively concentrated unaccompanied works.

The music was mostly from the 20th century, the exception being the Bach Chaconne, one of two unaccompanied works Mr. Kremer played.

We also encounter, four times, the quaint period practice of providing piano parts for the unaccompanied works of Bach and Paganini.

Here he plays the six unaccompanied works by Bach three sonatas, three partitas and the performances should be splendid.

Those qualities were in ample supply in Mr. Qin's performances of two unaccompanied works, one in each half of the program.

But at the Frick, Mr. Manze will be on his own, playing a deliciously taxing program of unaccompanied works.

Guitar solos range from unaccompanied works for a single guitar to compositions with accompaniment from other instruments.

Half of his program is devoted to demanding unaccompanied works by Bach and Bartok.

Here, Ms. Josefowicz tackles a collection of unaccompanied works that make sustained demands and require coloristic breadth and flexibility.