As an entrepreneur, he opened the Main Squeeze, at 19 Essex Street, between Hester and Canal Streets, in 1996. Part emporium, part performance space, part conservatory and part hiring hall, the store teaches, tunes, repairs and sells the accordion — prices range from about $100 into the thousands — and has become a mecca for players from around the world.Accordions can be heard in genres as diverse as jazz, rock, tango, klezmer and zydeco. But as Mr. Kühr well knew, the stigma of the wheezing polka box endures. He was quick to finger its source.“Blame it on Lawrence Welk,” he told The Star-Ledger of Newark in 1999.Walter Werner Kühr was born in Hanau, near Frankfurt, on Oct. 10, 1955, and began studying the accordion at about 6 years old. After earning a degree in piano and bassoon from the Musikakademie Frankfurt am Main, he was offered a position as a bassoonist with the Frankfurt Radio Symphony Orchestra.He declined, preferring to make his way as a jazz bassoonist and pianist. Settling in Hamburg, he supported his musical life with a series of odd jobs, among them gravedigger, wine seller aboard a streetcar and janitor in a brothel.Mr. Kühr moved to New York in the late 1980s to study jazz piano in Harlem, packing his accordion “almost as an afterthought,” his former wife, Claire Connors, said on Wednesday.The instrument would give him his livelihood, first as a performer on subway platforms and later as a visible, and audible, public ambassador.Mr. Kühr’s marriage to Ms. Connors ended in divorce. Survivors include his companion, Lauren Schwartz; his mother, Loni; and a brother, Gerhard. At his death — from lymphoma, Ms. Connors said — he lived in the Williamsburg section of Brooklyn.The Main Squeeze recently lost its lease and must close by Jan. 15. There are no plans to reopen it elsewhere, Ms. Connors said.