The only "real" rankings I know of are the NRC rankings. The NRC came out with their doctoral rankings in 2010 (based on years-old data by then, but anyway.....). The rankings are sort of confusing, so I'd say take a look yourself at: http://chronicle.com/article/NRC-Rankings-Overview-Music/124746/. In general, Harvard, Yale, and Princeton are all at the tippy top, Michigan a few notches lower, CUNY surprisingly low, but obviously these really have to be taken with a grain of salt because tied for #1 in S-rankings is Indiana's "Folklore" program. (?)