My explanation
Hi,
I'm glad you like the Using a personal computer as a multitrack recording device section. Thanks!
The reason for my edit is that the paragraph you are referring to:
 Some of the leading providers of multitracking software for a personal computer....
is repeated twice in the article. 

If you read the History section's last paragraph you will see it there. Then if you read the Using a personal computer as a multitrack recording device section, you will see it there as well with a slight addition.

I deleted this paragraph from the Using a personal computer as a multitrack recording device section, since it had to be deleted from either one of the two sections. 

The reason I deleted it from the Using a personal computer as a multitrack recording device section is because the History section has a line about how multitracking software has been written for personal computers:
 At the same time, with the power of the personal computer increasing, multitracking software was written for it ... 
And this is where this paragraph was originally.

If you see the edit differences between my deletion and your addition, you will clearly see the paragraph appearing  twice.

If you think that the paragraph belongs in the Using a personal computer as a multitrack recording device section instead of the History section, that works for me too!

Hope you will find my explanation adequate.