Notated on four staves, as though intended for some unspecified set of instruments (or even voices), these thirteen erudite contrapuncti, four canons, and an unfinished triple fugue-incorporating the letters of Bach's name-are often considered to be his musical testament. Shrouded in myths traceable to it's very origins, this is a puzzle for the performers and for the listeners alike, but when a brilliant string quartet takes up the challenge, a solution...