 Rosmini was born in New York City and grew up in Greenwich Village, where he learned guitar and began performing in clubs.During the 1960s, he was employed as the main jewelry photographer for Tiffany & Co..

His 1964 album "Adventures for 12 String, 6 String, and Banjo", predates much of John Fahey and Leo Kottke and other American primitive guitarists, which Kottke cited as an early influence.Rosmini was also a noted banjo player.