Louis "Moondog" Hardin, 83, a New York composer who in the 1960s stood out with his homemade robe, sandals, spear, scraggly beard and Viking helmet with horns, died Sept. 8 at a hospital in Munster, Germany, after a heart attack.

Mr. Hardin, a tall man who was blind and a bit gaunt, would take his place at the corner of 54th Street and Avenue of the Americas and play his homemade zither, sing in his distinctly atonal manner or beat a drum. At other times, he might recite some poetry. His street theater generally drew a crowd, and the crowd was his living in those days. The corner became "Moondog Corner."

But beneath his unquestionably eccentric exterior, Mr. Hardin was a talented composer. In his hours off the street, he wrote larger works--often based upon a form of the canon (or round)--and was welcomed as a guest to rehearsals of the New York Philharmonic.

"He was the greatest street person that New York has ever produced," said Robert Scotto, a professor of English at Baruch College of the City University of New York, who is working on a book on Mr. Hardin's life.

Mr. Hardin was born in Kansas, the son of an Episcopal minister, and he grew up in Wyoming. He lost his eyesight at age 16, when a dynamite cap that he found on the railroad tracks blew up in his face. He studied music at the Iowa School for the Blind for a year before moving to New York in 1943 to continue his musical education, which at the time was rudimentary.

Mr. Hardin started as a percussionist on drums, many of which he built himself. Through the 1950s, he tried Latin music and jazz, recorded some albums and worked in a number of bands, including a Latin jazz ensemble improbably called "Moondog and the Honking Geese."

He became something of a celebrity after Walter Winchell mentioned him in a newspaper column. Diane Arbus photographed him and occasionally would buy him lunch at a cafeteria near Carnegie Hall.

When Alan Freed, the pioneering rock-and-roll disc jockey, moved his radio program to New York from Cleveland, he used one of Mr. Hardin's recordings, "Moondog Symphony," as his theme music and called his program "The Moondog Show." But according to Scotto, Mr. Hardin successfully sued over the use of the name. So the disc jockey changed the name of his program to "Alan Freed's Rock 'n' Roll Show." Freed is generally thought of as the originator of the term "rock 'n' roll."

In the early 1960s, Mr. Hardin's Viking persona took over. He performed with the legendary jazz bassist Charles Mingus at the Whitney Museum and later did a concert with Tiny Tim and Lenny Bruce. In 1967, he showed up in the avant-garde film "Chappaqua" with William S. Burroughs, Allen Ginsberg and Ravi Shankar, who also wrote the score.

Two albums of Mr. Hardin's atonal jazz and madrigals were released in 1969 and 1971 by Columbia Records and received good reviews.

He later played his drum with top avant-garde composers Philip Glass and Steve Reich at the Brooklyn Academy of Music.

In 1974, Mr. Hardin moved to Recklinghausen in what was then West Germany after traveling there for a radio concert. He lived on the streets for a year and was finally adopted by a German family who loved his work. A daughter in the family, Ilona Goebel, became his working partner. She became his copier and editor. He composed, recorded and occasionally performed in concerts throughout Europe.

At least 10 albums of his compositions have been released in Europe since 1977, and his collected works now include 300 canons in the form of madrigals, 100 keyboard works and a self-published four-volume "Art of the Canon."