As a studied student of inaction and detachment, Rosenberg was the embodiment of the beat movement's ideal of the hipster and was the model for the character Julian Alexander in Jack Kerouac's novel The Subterraneans (1958).
He was a painter of some talent and he played the piano with Charlie Parker, Zoot Sims and other jazz figures of the day. But if he remained an obscure figure of the beat movement it was because he found his calling early. Once the poet Allen Ginsberg had discovered him leaning languidly against a car parked in front of Fugazzi's bar on 6th Avenue in Greenwich Village, Manhattan, and dubbed its coterie of laid-back hipsters "the subterraneans", there was little more for Rosenberg to aspire to.
Following Ginsberg's lead, Kerouac recognised that Rosenberg in his twenties - a thin, unshaven, quiet and strange young man of imposing good looks - was the epitome of the aesthetic that shunned enthusiasm and scorned ambition. He adopted Ginsberg's title for his book but moved the locale to San Francisco to avoid the risk of libel action by the Greenwich Village regulars who populated its pages under fictitious names. Thus Rosenberg became Julian Alexander, a man Kerouac called "the angel of the subterraneans".
"They are hip without being slick," he wrote of the bar's denizens. "They are intelligent without being corny, they are intellectual as hell and know all about Pound without being pretentious or talking too much about it, they are very quiet, they are very Christ-like."
The son of a wealthy New York industrialist, Rosenberg served a year in the Army and studied briefly at the University of North Carolina. By the time he was discovered by Ginsberg he had already spent a year in Paris imbibing the Left Bank bohemian atmosphere of Cafe Flore and Cafe Les Deux Magots with James Baldwin, Terry Southern and other figures engaged in perfecting the attitudes and inflections of cool.
By 1950 he was back in New York. He opened a print shop in Greenwich Village and lived in a tenement Ginsberg called Paradise Valley, and later in an industrial loft in a bad neighbourhood long before it became fashionable.
Naturally, drugs were a staple of the scene and on one legendary occasion, Rosenberg and his friends at the San Remo bar intercepted a shipment of the hallucinogen peyote from Exotic Plant Co of Laredo, Texas and congregated at his loft for an all-night party and jazz jam session. But if marijuana was universal among the hipsters, it was opiates that set the subterraneans apart. Rosenberg was a heroin addict for most of his life and appeared as a character in William Burroughs' book Junkie (1953).
As his habits did not lend themselves to a productive life, Rosenberg at least had the foresight to marry a schoolteacher who remained charmed enough by his ways to support the family while he continued to paint, play music, and amuse himself and his friends.
One of his sons is a New York City police detective who specialises in drug enforcement.
Anton Rosenberg, artist and painter: born 1926; married (three sons); died Woodstock, New York 14 February 1998.