Sinatra Jr. was on his Sinatra Sings tour and had been in Daytona Beach for several days rehearsing. He was scheduled to perform next on Thursday at the 2,000-seat Mahaffey Theater in St. Petersburg, Florida., and then on May 19 at the 2,400-seat Adler Theater in Davenport, Iowa.
He began performing in his teens and carried on a career of entertaining across mediums for the past 50 years. More recently, he had a guest spot playing himself on The Sopranos and appeared on two episodes of Family Guy.
In December 1963, the Sinatra family endured a terrible ordeal when Frank Jr., then 19, was kidnapped from a hotel room in Lake Tahoe, California, and held for a $240,000 ransom. He was released unharmed.
Frank Sinatra's first two kids were each born in Jersey City, New Jersey: Nancy ("These Boots Are Made for Walkin'") on June 8, 1940, and Frank Jr. on Jan. 10, 1944. Tina Sinatra was born on June 20, 1948, in Toluca Lake, Calif., after the family moved west.
In addition to his sisters, survivors also include his mother, Nancy Sinatra Sr., the first of Frank Sinatra's four wives, and his son, Michael.
His father died at Cedars-Sinai Medical Center in Los Angeles on May 14, 1998, at age 82 after suffering a heart attack.
Sinatra's sister Nancy confirmed the news of his death on Facebook.