I'm trying to get a sense of what type of math to brush up on in order to take a course based on the book A First Course in Modular Forms by F. Diamond and J. Shurman. The text claims to be accessible to advanced undergraduates / first year graduate students with adequate preparation in algebra and complex analysis; I'm trying to get a sense of what parts of these subjects are heavily used enough to warrant some review.
I will have approximately 4 weeks where I'll be relatively responsibility free, and so should have a significant amount of time each day to prepare. I'm told to favor group theory over complex analysis, but I'm looking for a bit more specific advice. My current plan is to go through Chapter 5 of Robert Ash's algebra notes. Keep in mind I've seen all the material in the notes before, and am just refreshing myself. I also plan to start Stein & Shakarchi's Complex Analysis — again, I've seen much of this material before also, but certainly need a refresher.
So I guess my question is — where does the heavy duty algebra / heavy duty complex analysis show up?