Stephen Sondheim (b. 1930), who wrote the lyrics for West Side Story, was himself an aspiring composer. He has gone on to write words and music for a string of successful musicals with an intellectual bent, such as A Little Night Music (1972), Sweeney Todd (1979), and Into the Woods (1987). Sweeney Todd in particular pushed at the border between musical and opera, as Gershwin had done forty years earlier in Porgy and Bess.

Meanwhile the musical in the 1960s began to acknowledge the rock revolution. Prominent rock musicals were Hair (1967; the latest revival was in 2009), Grease (1972), and Rent (1996). Rock musicals have had to share space on Broadway with more conventional fare, often from abroad, such as Les Misérables (Les Mis, 1980), Cats (1981), and The Phantom of the Opera (1986). Some of these are still running.

Written for the stage, musicals have often been filmed with great success, from Show Boat to Rent, not to forget West Side Story. Back in the early days of movie musicals, Walt Disney had the idea of creating musicals directly for animated full-length films, including Snow White and the Seven Dwarfs (1937) and Pinocchio (1940). In the 1990s this tradition was revived by the Disney studio with films such as Beauty and the Beast (1991) and The Lion King (1994). Again we see musical theater reinventing itself — from opera to operetta, from operetta to musical, from musical to filmed musical. Such reinventions will surely continue in the future.

Beyond Broadway and Hollywood, throughout all this time, musical comedy has thrived in the annual student revivals of Broadway hits at thousands of colleges, high schools, junior highs, and summer camps around the country. Take part in one of these, and it will expand your whole idea of music.