Contrapunctus VIII from The Art of the Fugue
What is a double or triple fugue?
A double fugue is based on two subjects. A triple fugue is based on three subjects. The subjects can be presented at the exposition or they can appear separately before being combined later as in this fugue.
J. S. Bach Contrapunctus VIII from the Art of de Fugue (Die Kunst der fuge BWV 1080) is a three voice triple fugue based on these subjects:
The third subject is a variation of the main subject of the Art of the Fugue.
Measures 1 to 38 are based on the first subject. The second subject appears for the first time in measure 39 and the third subject in measure 94. It is not until measure 149 that all three subjects will appear at the same time.