Here's the direct link to the Berklee College of Music's free Music Theory Handbook, Volume 1.
When I tried downloading it in the Opera web browser, it said it was a jpg/jpeg file and got saved to my desktop with the filename:
If that happens to you, then save the file and just rename it to:
I've uploaded the music theory handbook to my Nickleus Music Theory and Composition Examples archive, if you want to download it there instead.
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