Data based on 2 reviews.
Music theory/history tests are few and far between, and are generally intuitive, so it shouldn't be a major stressor. It is always helpful to take private lessons, play in conglomerate bands, and practice outside of band to succeed in class. Aside from the concert music, he'll do some sight reading, scale exercises, and warm up scales, but doesn't teach music theory consistently. Lastly, it doesn't take much effort to get in the advanced level bands, if you have a passion for music it will show in your attitude and your playing!
This is a very fun class! Just try to take private lessons outside of the class to practice it.