Earlier this week on Ether Game, we explored a dozen pieces on the theme of the number twelve in celebration of December, the 12th month of the year. The Ether Game Brain Trust wants to make it a Baker's Dozen! See if you can guess this twelve-themed piece. The answer is below.

Johann Sebastian Bach (1685-1750) The Art of the Fugue: Contrapunctus 12 and 13

The Emerson String Quartet

Album: Bach: The Art of the Fugue - Emerson String Quartet

Bach began work on "The Art of the Fugue" around 1740, and revised and expanded the work several times. The final version was probably largely complete by about the end of 1749, but Bach died before the entire work appeared in print. And His sons. especially CPE Bach took charge of the publication and the work appeared posthumously in the spring of 1751. Bach calls this movement the Rectus and the following movement the Inversus, that's because the 2nd movement is also the first, but flipped on a horizontal axis. That makes both these pieces Mirror Fugues!