Following positions at the Rialto and Rivoli theaters, he was hired by Samuel "Roxy" Rothafel as the musical director of the Capitol Theatre's 77-member orchestra in New York. It was at the Capitol that Rapée made his most famous classical arrangement of Franz Liszt's "Hungarian Rhapsody, No. 13". While at the Capitol, he pioneered orchestral radio broadcasts over station WEAF as part of the "Roxy's Gang" programs. He also engaged Eugene Ormandy as the Capitol's concertmaster and assistant conductor. The Capitol orchestra made a number of commercial recordings under Rapée's direction in 1923-24 for the Brunswick-Balke-Collender Company.