In 1940, Bernstein attended the inaugural year of the Tanglewood Music Center (then called the Berkshire Music Center) at the Boston Symphony Orchestra's summer home. Bernstein studied conducting with the BSO's music director, Serge Koussevitzky, who became a profound lifelong inspiration to Bernstein. He became Koussevitzky's conducting assistant at Tanglewood and later dedicated his Symphony No. 2: "The Age of Anxiety" to his beloved mentor. One of Bernstein's classmates, both at Curtis and at Tanglewood, was Lukas Foss, who remained a lifelong friend and colleague. Bernstein returned to Tanglewood nearly every summer for the rest of his life to teach and conduct the young music students.