I am a singer that loves the style of Frank Sinatra. Did he ever use the Unidyne Model 55?
From the book "Sessions with Sinatra: Frank Sinatra and the Art of Recording" by Charles L. Granata; ISBN 1-55652-356-4; page 22:
"While the RCA44 [ribbon microphone] was omnipresent for all of Frank Sinatra's radio and recording sessions, it was absent during his live stage appearance. The less-controlled environment of live performance required a studier microphone, and for in-person performances during the 1940s, the Shure Unidyne Model 55 series and the Altec 639B models were the instruments of choice. The Shure 55 sported a sleek, modern ribbed design that kept it a mainstay of the industry from the late 1930s to the mid 1960s. These mics were originally identified with the early rock-and-roll era; today, they are sought after as both working microphones and props for modern musicians who wish to add a classic, retro look to their live performances and music videos."