Crazy Shoenberg Counterpoint Exercise

I've been working through Shoenberg's Preliminary Exercises in Counterpoint, diligently mimicking all the exercise examples in each chapter, until I came to the last example in chapter 10. It's a canon in 3 voices with the 2nd voice starting a 7th below the 1st and the 3rd starting a 4th below. Apparently, he considered this combination strenuous enough that he suggested it as something to be avoided altogether and the example he gave for it looked like such a mess that I decided to take up the challenge and see if I could do better. To make matters worse, his example modulates through 3 other keys and is a perpetual canon, so I also made sure to include those aspects, you know, just to make the whole thing utterly impossible. The result, I think, turned out better than his example but, after the better part of today working on it, is also quite a mess.I guess I'm posting this as a challenge of sorts. I didn't consider aesthetic value when working it out, only Schoenberg's rules for counterpoint, so it's terrible as music. I even got sloppier as I went on and more accepting of errors due to mental exhaustion. Anyway, I counted 25 errors (give or take depending on how strict one is) and I'm a bit curious to see if anyone, who wants to waste a day, can complete the task with fewer.I marked out my errors with slurs and Xs.

Crazy Shoenberg Counterpoint Exercise

I've been with Schoenberg since June of 2010 and am in the middle of the Sixth Compositional exercise. I'm not yet ready to tackle canons and the exercise you mention but will let you know when I'm ready to attempt it. Other than that, just dropping a short note here, thinking it might be interesting to compare notes and exercise results with someone else who is going through this book.