Hey Guys It's Jim Riley here.
I'm finishing up a book for Hal Leonard on this subject and would be glad to answer any questions on the subject. You can find me at my website, www.jimrileymusic.com
Or ask away here.
The best thing about the system is that since each number standing alone represents a measure you can clearly see how many measures are in a particular section without counting them. .Thats because they are grouped in musical phrases (usually 4 bar phrases.)
The biggest things as a drummer to look out for is that little < sign above and to the left of a number. That tells you to attack that chord an eighth note sooner. It is called a push. Normally two chords to a measure means you play the first chord for two beats, then change on beat three chord. When you see that push in the second measure of the ch, that would mean play an accent on the and of two instead of beat three
The other thing to look out for is the diamond, Like the 4 at the end of the ch. That means stop playing the groove and play a whole note on your chrash and bass drum. Hope this helps...