The mid-twentieth century baby boomers provided a growing market for children's music. Woody Guthrie, Pete Seeger, and Ella Jenkins were among the politically progressive and socially conscious performers who aimed albums at children. Novelty recordings like "Rudolph the Red-Nosed Reindeer" (a Montgomery Ward jingle that became a book and later a classic children's movie) and the fictional music group Alvin and the Chipmunks were among the most commercially successful music ventures of the time.