Gerome Ragni, co-author of Hair, the hit musical that for millions around the world became a theatrical summing-up of the rebellious youth culture in the 1960's, died Wednesday in New York City.  He was 48 years old.

He died of cancer, said his son, Erick.

The book and lyrics for Hair by Mr. Ragni and James Rado, were considered the perfect compliments to the music of Galt MacDermot in portraying an iconoclastic era of sexual liberation, anti-war movements, egalitarianism, and a general rejection of materialism in favor of universal love - in short, the age of the flower children.

Bursting on the world in  1967 at the New York Shakespeare Festival; Hair was rewritten for a move a year later to Broadway, where it played 1750 performances.  Within 10 years it grossed $80 million from performances in cities from Rio de Janeiro to Tokyo.

Among it's songs were "Aquarius", "Good Morning Starshine" and others that addressed issues like drugs, racism, and religion.  The show also included nudity and profanity.  It was revived on Broadway in 1977 and was made into a film by Milos Forman in 1979.

Mr. ragni and Mr. Rado, both of whom were in their 20's, played leading roles.  At one point they were briefly barred from the theater by the show's producer, Michael Butler, for what was characterized as objectionable behavior on stage.  With his dark, flashing eyes and unruly mop of hair, Mr. Ragni especially fit the world he and his colleagues had created.

Hair was the most acclaimed element of Mr. Ragni's career as an actor, librettist and lyricist.  He and Mr. MacDermot teamed up again in 1972 to create a much-heralded musical called Dude, but the show was a critical and box-office disappointment.  Another Ragni show, Jack Sound and His Dog Star Blowing His Final Trumpet on the Day of Doom, with music by Steve Margoshes, was performed Off Off Broadway at the Ensemble Studio Theater in 1977.

In the last five years, Mr. Ragni again associated himself with Mr. Rado and Mr. MacDermot in working on a new musical Sun, which has yet to be produced.

One of the younger members of a large family in his native Pittsburgh, Mr. Ragni first began acting in high school.  In 1963 he won the Barter Theater Award as an outstanding young actor.  His stage appearances included a broadway production of Hamlet with Richard Burton in 1964, and Off Broadway roles in Viet Rock, Hang Down Your Head And Die, and The Knack.  Among his film credits was Agnes Varda's Lion's Love.

In addition to his son, he is survived by his mother, Stephanie Williams Ragni, five sister and two brothers.