He died of heart failure at the Torrance Memorial Medical Center in California on Saturday (29Jun13).
Born in San Diego, California, Smith began studying piano at a young age and joined the Johnny Richards band in 1941.
He left the group to become a member of the Les Paul Trio in 1946 and he later moved to Los Angeles to launch a career as a studio musician and solo artist.
During his lifetime, he recorded more than five dozen records and performed with a string of music greats, including Bing Cosby, Nat King Cole and Doris Day. He also spent 11 years with Fitzgerald, and another four years with Sammy Davis, Jr., working as their conductor and pianist.
The star continued performing up until his death and over the last few years toured with his singer wife, Annette Warren. The couple was slated to headline a show at the Catalina Bar & Grill in Los Angeles on 17 July (13).
Smith is survived by his two sons Gary and Paul, as well as a daughter, actress Lauri Johnson, who starred in Meg Ryan's City of Angels and Keri Russell's Waitress.