Search Primo (the USC Libraries' catalog) for books at USC. Books specifically on musical subjects are located in the Music Library. Interdisciplinary publications, often including the interaction of music and business, are sometimes located in Doheny Memorial Library.
Books on music are classified by the Library of Congress as ML (Music Literature) or MT (Music Theory and Instruction). See here for specific distribution of subjects.
Physical music industry books are located at (and around) ML3790, currently located in room G-17 of Doheny. See here for a list of titles under that call number.
E-books are of course increasingly important, though not always available for institutional subscription or license: see here for a list of e-books with a music industry subject heading.