Books about music (including composer biographies) are on the basement level of the library. Follow the stacks around to the ML410s. ML410 is the call number for books specifically about composers, and within that call number the books are arranged (roughly) by composer last name.
You can also search the catalog using a subject search for books about your composer. Just choose "subject" from the drop down below and enter your composer's name (last name, first name) into the search box. Text yourself the call number before heading down to the basement to save time!
So what's the point in analyzing and comparing biographies?