I notice in his BWV 565, more well known as Toccata and Fugue in D minor, what looks like a lot of parallel octaves in the fugue. I have studied counterpoint before and every counterpoint resource I find says "Absolutely no parallel 5ths or 8ves between any 2 voices. If you have an octave or a fifth, use stepwise motion that is either contrary or oblique to avoid parallels" or something along those lines.
Here is the video starting at the fugue:
As you can see, right away, the subject is stated in octaves. There are several other moments where the octaves are very obvious. And these, if I'm not mistaken are parallel octaves, the same thing that every counterpoint teacher tells you to absolutely not use. I have been told by several people that these parallel octaves are not the same as the ones you need to avoid because of the specific voices they are in. Um, how does voice arrangement make any difference? Why isn't Bach breaking the rules every time he uses parallel octaves in this fugue? I thought parallel octaves were to always be avoided in Baroque counterpoint and that it is only really once you get to classical era and romantic era counterpoint that you are free to use octaves as much as you would like as long as the whole piece isn't just a string of octaves.
So I can understand the octave theme here in Beethoven's Grosse Fuge:
But why is Bach not breaking the rules of Baroque counterpoint with the parallel octaves in his Toccata and Fugue in D minor?