okay SO the Glenn Miller tune "Pennsylvania 65000" - finally looked it up and it turns out to be the purported oldest still-used phone number in NYC, the Pennsylvania Hotel from 1919. Apparently standardized phone numbers didn't happen till 1947.
The hotel went out of business in 2020 during Covid, and there's now a big hole in the ground where they're going to put up a tower of some sort, so it's good to know Seattle isn't the only city gleefully demolishing stuff to put up new stuff.