Johann Sebastian Bach

Let there be no confusion about it: J.S. Bach's Fugue in G minor for organ, BWV 578, is known as the "Little" G minor not because it is a work of small importance or even because it is an unusually short work in its own right, but simply so that it and the much longer and later "Great" G minor Fantasia and Fugue, BWV 542, might not be mistaken for one another. Bach probably composed the "Little" G minor Fugue sometime between 1703 and 1707, when he was a young, up-and-coming organist in the city of Arnstadt.

The "Little" G minor's four-and-a-half-measure subject is one of Bach's most widely recognized tunes. It is worked out in four voices, the pedal voice being honored as the full equal of the three manual voices -- even to the extent that the feet are required, in one electrifying passage late in the Fugue, to have a go at a sixteenth note figuration of the countersubject. During the episodes, Bach employs one of Corelli's most beloved sequential gestures: imitation between two voices on an eighth note upbeat figure that first leaps up a fourth and then falls back down one step at a time. And those who love to find precise, mathematical structural divisions and markers in Bach's music will enjoy noting that it is in the 33rd measure -- one measure shy of the exact midpoint of BWV 578 -- that Bach first introduces the subject in a key outside the tonic-dominant loop of the exposition.

-- AllMusic.com