Colleges of music and university schools of music are tertiary level institutions, and they may either be independent or part of a university. Many music schools originated as vocational training centres for would-be professional musicians, often outside the main academic structure. These institutions have retained an emphasis on performance into the 21st century, while also adopting a more formal academic approach. On the other hand there are university music departments, which originally placed more emphasis on academic study of music, but often place greater emphasis on performance now than they did in the past. The two groups overlap more than they used to, with the specific balance of vocational training and academic study varying from one institution to another