Frank Sinatra was arguably the most important popular music figure of the 20th century, his only real rivals for the title being Bing Crosby, Elvis Presley, and the Beatles. In a professional career that lasted 60 years, he demonstrated a remarkable ability to maintain his appeal and pursue his musical goals despite often countervailing trends. He came to the fore during the swing era of the 1930s and '40s, helped to define the "sing era" of the '40s and '50s, and continued to attract listeners during the rock era that began in the mid-'50s. He scored his first number one hit in 1940 and was still making million-selling recordings in 1994. This popularity was a mark of his success at singing and promoting the American popular song as it was written, particularly in the 1920s, '30s, and '40s. He was able to take the work of great theater composers of that period, such as Jerome Kern, Irving Berlin, George Gershwin, Cole Porter, and Richard Rodgers, and reinterpret their songs for later audiences in a way that led to their rediscovery and their permanent enshrinement as classics. On records and in live performances, on film, radio, and television, he consistently sang standards in a way that demonstrated their perennial appeal.