Before the 60s were the 60s, there was the Bell Telephone Hour. Here we see not only sincere young men with great voices singing folk music The Chad Mitchell Trio (they are actually socially aware risk-taking satirists), but a pre-Byrds and very young Roger (Jim) McGuinn and an advert for the Princess phone — it’s not for guys. (from January 19, 1962)
Camilla writes about Jim/Roger’s Chad Mitchell experience here.