J.S. Bach's Suites for Violoncello , as one of the best compositions ever written for an unaccompanied instrument, has been a staple of the viola repertoire ever since it was first transcribed into alto clef. The six suites explore a variety of tone colors and range in difficulty, providing a continual challenge throughout a player's lifetime. Since no manuscript in Bach's handwriting exists, multiple editions of the suites are available.