OK, I dug the real figures out from http://peacock.adm.oberlin.edu/ir.html
under the Admissions tab in the Electronic DataBook.
Conservatory Applications - 1132 Freshman, 93 Transfer, 40 Graduate
Conservatory Admissions - 311 Freshman, 20 Transfer, 7 Graduate
Conservatory Enrolls - 138 Freshman, 13 Transfer, 5 Graduate
Double degrees (included in above numbers) - 40 Freshman, 1 Transfer
So the overall con admit rate for freshmen is 27.5% and their yield is 44.4%.
Check out http://peacock.adm.oberlin.edu/www/sche25/
for a historical perspective on these numbers.