If you got charged twice you should show proof of double purchase of the same product with the same iTunes account to the iTunes Support staff and you'll be refunded.
Here is link to them:
http://www.apple.com/support/itunes/
Is there a Bluegrass style pack in the works? Should be pretty easy bass lines. No drums. Maybe mandolin chops instead on 2 and 4? or even guitar strums.
Awesome app. Lovin' it since it started.
Any chance of being able to set up your own Player styles?
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