I run a website called GuitarTheoryRevolution.info and have an e-course for sale which is... all about music theory for guitar players!

Check out the regular sales page here (price USD$47 + local taxes)

http://www.guitartheoryrevolution.info/blog/guitar-music-theory-for-beginners-cb/


Or go here to pay the equivalent of $20 in BTC (so more than a 50% discount)

http://www.guitartheoryrevolution.info/blog/guitar-theory-revolution-store/

Scroll down for the Bitcoin payment button.

Any questions about the course, just let me know.