North American Numbering Plan usually shown in capital letters, were dialed. Later, the third letter, where implemented, was replaced by a digit, or an extra digit was added. This generally happened after World War II, although New York City converted in 1930. The adoption of seven-digit local numbers (2L-5N) was chosen as the requirement for direct distance dialing and progressively deployed starting the late 1940s. The famous Glenn Miller tune "PEnnsylvania 6-5000" refers to telephone number PE6-5000, a number still in service at the Hotel Pennsylvania (212 736-5000) in New York. Similarly, the classic film "BUtterfield 8" is set in the East Side of
Glenn Miller (a former arranger for Tommy Dorsey), Billy May and to a much smaller extent, George Williams, who worked very briefly with the band as well as Andrews Sisters arranger Vic Schoen According to Norman Leyden, "[s]everal others [besides Leyden] arranged for Miller in the service, including Jerry Gray, Ralph Wilkinson, Mel Powell, and Steve Steck." In 1943, Glenn Miller wrote "Glenn Miller's Method for Orchestral Arranging", published by the Mutual Music Society in New York, a one hundred sixteen page book with illustrations and scores that explains how he wrote his musical arrangements. "Major Alton Glenn Miller (Army Serial No.