Estate near Lenox, Mass., which in 1937 was offered to the Boston SO so that it could establish the Berkshire (now Tanglewood) Music Center for instruction in conducting, opera and instrumental perf., and composition at a summer school founded by Koussevitzky in 1940. The summertime Berkshire Fest., directed by the incumbent cond. of the Boston SO and his guests, has over the years accommodated thousands of students and enthusiasists. Among operas which have received their Amer. premières there are Idomeneo, La clemenza di Tito, Zaide, Peter Grimes, Down by the Greenwood Side, Maderna's Satyricon, and the 1806 vers. of Fidelio.