<p>Northwestern University offers a summer program in acting, although I do not know if music theatre is an option. The program is called Cherubs, but it may only be open to high school students. Several participants have posted on CC that they were subsequently admitted into Northwestern’s famed theatre/acting major which includes an “by audition only” musical theatre concentration beginning in the sophomore year. (Time magazine recently published a Top Ten list for the past decade and 3 of the top 5 of the top ten plays of the decade were written or directed by current Northwestern theatre faculty, including the top play of the decade. One of the 3 of the top 5 plays was originally written, directed, produced & acted entirely by Northwestern University students & faculty.)
Also contact Connecticutt College regarding a professional & student theatre program during the summers on campus. I don’t know the details, but my understanding is that it is a highly respected summer program.</p>