I'm not going to the upcoming one, but have been to one (at GC in Minneapolis, I think) in the past.
I was fortunate enough to be at the Musician's Institute when he did a workshop there. It was one of the most informative mornings I've ever had.
The GC was a whole different ballgame. Many of the participants had no understanding of even the basics so he spent much time trying to answer basic questions e.g Why is the flatted fifth okay to play in a blues scale type of thing.
Will you learn something? Al, I think I remember from one of your other posts that you're at music school right now so it depends on who else is going to be in the audience.
But I would definitely go, because after the event he will be available to discuss in depth stuff with you.
And he's a really nice guy to meet, too.
Enjoy.
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