Les Cauchi, a friend and original Brooklyn Bridge member, said Maestro - born John Mastrangelo - died late Wednesday in Florida. His last residence was in Cape Coral, Fla.
After beginning his career in the 1950s with The Crests - one of the first interracial singing groups - Maestro joined a local New York group, The Del-Satins. It merged with a Long Island band, The Rhythm Method, to form Johnny Maestro and The Brooklyn Bridge in 1968.
Hits by the rock 'n' roll and doo-wop group included "The Worst That Could Happen," which Cauchi said earned "gold record" status with a million sales.
Cauchi said the group performed that song on "The Ed Sullivan Show." Other hits included "Blessed is the Rain," "Welcome Me Love" and "You'll Never Walk Alone."
Cauchi recalled that another well-known song, "Your Husband, My Wife," drew controversy when it was released in 1969 because it dealt with infidelity - a touchy topic during that era.
"Johnny was a class act. He was truly a gentleman," singer Dion DiMucci said on Facebook. "He sang `You'll Never Walk Alone' like an angel. ... We thank you for the beautiful trip you took us on. Love and peace."
"Dion reached out to John over the last couple of months, when Johnny was sick, to encourage him and give him some spiritual guidance," Cauchi said.
The band got its name after a manager declared it would be "harder to sell than the Brooklyn Bridge," Maestro once said. He performed at arenas, amphitheaters and casinos throughout the U.S. and Europe.
"He's considered one of the premier vocalists in rock 'n' roll - and one of the nicest, most sincere perfectionists in music," said Cauchi.
"Maybe now the Rock and Roll Hall of Fame will recognize him," said veteran radio host, author and music historian Bruce "Cousin Brucie" Morrow.
"Of all the talent, Johnny was the smoothest," said Morrow, who worked with Maestro many times. "He probably sounded more like his recordings live than any other performer. He always held true to the music and treated it with great respect."
Maestro's last performance was Jan. 17, when The Brooklyn Bridge was among groups appearing at the Mohegan Sun Arena in Connecticut. It was billed as "Bowzer's Ultimate Doo-Wop Party."
"As frail and weak as Johnny seemed, I knew he didn't want to have to cancel," host Jon "Bowzer" Bauman said in an e-mailed statement. "I told him afterward it was the most courageous performance I'd ever seen. As frail as he looked, that's how strong he sounded.
"It was a privilege to have known him, and it was thrilling to have listened to him," said Bauman.