83 years ago on April 28th, 1940
'Pennsylvania 6-5000' is first recorded by the Glenn Miller Orchestra
The song would become a jazz standard and make one of New York's phone numbers internationally known. The title references the style of using a word to remember a phone number's first digits, with the PE from 'Pennsylvania' representing numbers beginning 73 in the area around Penn Station. Combined with Manhattan's area code, the number is 212-736-5000, which will still to this day connect you to the Hotel Pennsylvania!
Here's the Ithaca High School Chamber Orchestra under the direction of Bill Makin performing Pennsylvania 6-5000 for their winter concert in 2016: