Ragni was next in Viet Rock (1966) in New York and soon after this he and Rado began work on what eventually became Hair. The pair wrote the book and lyrics, with music by Galt MacDermot, and the show became a huge international hit after it opened on Broadway on 29 April 1968. Rado and Ragni both played leading roles and Ragni also appeared in productions of Hair in Los Angeles and on tour throughout the country. He continued to write and Dude, The Highway Life, with music by MacDermot. opened at a specially remodelled Broadway Theatre in October 1972 where it ran for only 16 performances. Ragni and Rado worked with Steven Margoshes on Jack Sound And His Dog Star Blowing His Final Trumpet On The Day Of Doom (1977, aka YMCA).
Success brought financial security but dissatisfaction to Ragni; his marriage failed and he drifted through various causes, some of them extreme. In the early 90s he worked again with Rado and MacDermot on a revised version of Hair and these three, plus Margoshes, also developed a new show, Sun. A recording of this score was made for Rado’s own recording company. Ragni also worked with Rado on the latter’s show, Rainbow Rainbeam Radio Roadshow: The Ghost Of Vietnam (aka Billy Earth), and at the time of his death from cancer he and Rado were developing a sequel to Hair.