Cocktail Party Fact: Bach wrote the Musical Offering after a visit to Frederick the Great. Frederick gave him a theme to improvise on and Bach complied. After he returned home, Bach decided the theme had more potential and turned it into a little library of Baroque chamber pieces.

Commitment Factor: About one hour for the whole collection. Some of the pieces are only a few minutes long, however.

Vital Statistics: A collection of 13 musical pieces composed around a single theme. The Musical Offering contains 9 canons, 1 trio sonata, one “canonic fugue”, and 2 ricercare.

What to Listen For: The Musical Offering can create some haunting moods, but it is primarily an exercise in musical craftsmanship. The canon, the ricercar, and the fugue are all contrapuntal forms in which a theme harmonizes with itself as it is played in different voices. They are sophisticated, complex versions of rounds such as Row, Row, Row, Your Boat. The trio sonata is a standard Baroque chamber form. It’s written for three voices but it usually requires four instruments. One of the voices is an accompaniment played by two instruments: a bass instrument, such as the cello, plays a bass line and a chording instrument, such as the harpsichord, develops harmonies and adds special effects. The other two instruments play a kind of duet over the accompaniment. They can be a pair of violins, a violin and a flute, or almost any other combination the composer and the musicians want to try. Bach takes Frederick’s peculiar theme, runs it through his inventive mind, and produces thirteen examples of Baroque musical tapestries.