Not bad!
It certainly is pretty interesting to know that Flash is being used for great works such as this one. I'm no music expert but I believe you managed to cover a good amount of material. It went to the point, and explained in good detail while still keeping it simple so it wasn't confusing at all. It was very appealing visually and the illustrations helped in getting the message through.
However, there were some bugs in the flash. The menu wasn't working properly. I clicked for the tab tutorial and all I got was a blank screen. The Back button also had some problems as well as the audio. The music kept playing over itself.
Overall, it was a good tutorial. I'm planning on learning to play the guitar pretty soon, and this really caught my attention. If anything, I would just like you to expand the tutorial so it covers more basics, specially for the tab part! Good luck on your future projects.