John Bubbles, 84, an inventor of rhythm tap dancing who portrayed the original Sportin' Life in George Gershwin's operatic classic "Porgy and Bess," died May 18 at his home in Los Angeles. He had been partially paralyzed since a 1967 stroke.

He was part of the vaudeville tap dance team of "Buck and Bubbles," one of the first black acts to play at Radio City Music Hall. Mr. Bubbles later appeared on Johnny Carson's "The Tonight Show."

Before Mr. Bubbles developed rhythm tap dancing, most tap-dancing was done on the toes. He changed it by dropping the heels and adding the toes to make a syncopated sound, then he dropped the tempo to add more creative steps.

He was born John Sublett in Louisville. He began his show business career as a singer at the age of 7. The lanky theater usher and bowling-alley attendant and his pal, Ford (Buck) Washington, became "Buck and Bubbles," perhaps vaudeville's best-known dance team. Performances at the Kentucky State Fair and at a Louisville theater brought an offer from The Kiss Me Company, one of vaudeville's touring troupes.

By 1919, they were playing the Palace Theater in New York. Eventually they moved to Broadway where they were billed with Al Jolson, Burns and Allen, Eddie Cantor, Kate Smith and Danny Kaye. "Buck and Bubbles" became the second black act to star in Ziegfeld Follies in 1931 and later played the London Palladium.

After the Follies, "Buck and Bubbles" returned to vaudeville for several years until Gershwin heard Mr. Bubbles' untrained but operatic quality voice and asked him to become the boisterous Sportin' Life in the all-black "Porgy and Bess," produced in 1935. Buck Washington died in 1955.

Mr. Bubbles is survived by his wife.