I had a chat with Joe Labriscia from the Four Seasons in 1971 about Crewe. I had heard that his contribution to producing was to walk in to a recording session, listen for 30 seconds, make a suggestion and then walk out. Joe agreed, but he said that Crewe's suggestion was always the right one, so nobody complained.
Crewe had the same gift as the legendary Bertha Porter of WPOP in Hartford. She could listen to 15 seconds of a record and tell you if it would be a hit and to whom the song would appeal. I confirmed that story with Joey Reynolds, who worked with her in the early Sixties, in a phone conversation in 2002.
She knew Bob Crewe, and they were apparently savants of popular music.
Got some music connections P.:)