Ronnie D'Addario was born and raised in Manhattan, in the heart of the theater district, across from the Ed Sullivan Theater. He started playing guitar at the age of ten after seeing The Beatles on Ed Sullivan. He began singing and playing, including bass guitar, professionally in his early twenties. He grew up listening to 1960s pop music.
​
​Ronnie played guitar with Tommy Makem, of The Clancy Brothers and Tommy Makem fame, for two decades, in concert, recordings, TV shows, and the stage.

His credits include an appearance on the Rosie O'Donnell Show, TV commercial jingles, and six PBS shows with Tommy Makem (where he performed with Judy Collins. He has performed at Carnegie Hall, the Guinness Fleadh at Randall's Island, Lisner Auditorium, Wash. DC, and Mechanic's Hall, Worcester, MA. Ronnie also produced the album, "Live At the Irish Pavilion," a favorite among Makem fans, and several other artists.

Along with his professional works he recorded plenty of songs on his own in Pop & PowerPop style that have been ultimately collected in two triple Cds and two Lps by You Are The Cosmos record company. In 1993 released a record with his band The Rock Club - Wet Money to critical aclaim, then went back to his own recordings. His sons Brian and Michael formed a band called The Lemon Twigs to find great success all over the world with a music style not really that far from his father's.