Note the long-line melody which, however, begins as a brief, 5-note germ motive that ascends a third and returns with different notes, then ascends again, growing to a tritone and returning. The third phrase is the climax phrase, followed by a fourth phrase before the Answer begins at m. 5. Even after the Answer, the original subject continues its independent way developing the germ motive with which it began. Meanwhile, you should be aware of the particular way in which the successive Subject and Entry pitches are arranged. The procedure is similar to a wedge in which the Subjects enter successively a fifth higher, thus A - E - B - F#(Gb) - C#(Db) - Ab - Eb, while the Answers enter successively a fifth lower, thus A - D - G - C - F - Bb - Eb. Thus there is a Subject or Answer on each of the 12 pitch classes and the climax of the piece is reached when the Subject and Answer both reach the tritone in opposite directions on Eb, m. 56.
The wedge:
Eb
Ab
C#(Db)
F#(Gb)
B
E
A
D
G
C
F
Bb
Eb