Measures 39 to 93

The second subject appears for the first time in measure 39 in the alto while the soprano plays the first subject. There are two more appearances of the two subjects in measures 39 and 53:

All voices play each subject in measures 39 to 52 as shown in this table. In measure 43 the subjects are inverted at the octave (see invertible counterpoint):

Measure	Subject 1	Subject 2
39	Soprano	Alto
43	Bass	Soprano
49	Alto	Bass

After an episode (measures 53 - 60) both subjects appear two more times. Soprano and alto in measure 61 and bass and soprano in measure 67:

Measure 61 starts F major but we return to D minor in measure 64. Bb major is the key in measure 67 and the subjects use again inversion at the octave.

An episode begins in measure 71 using fragments of the first subject (quarter notes) and the second subject (eighth notes). The highly chromatic section starting in measure 73 is a cycle of fifths:

Both subject appear again in measure 81. The passage looks similar to measure 39, yet the alto starts with a B natural instead of B flat and the key is now A minor. Let's compare both sections:

An episode based on both subjects begins in measure 85 and will lead us to measure 94 where the third subject is presented for the first time.