Tom Dreesen, the comedian and comic actor whose sharp delivery and amiability made him a favorite not only with audiences but of show biz kingpins like Johnny Carson and Frank Sinatra, died today. He was 86.

His death was announced by a spokesperson for his family. A cause was not stated.

“For more than five decades, Tom Dreesen brought laughter, heart, and humanity to audiences across America,” the statement said. “A proud native of Harvey, Illinois, Tom built a remarkable career through perseverance, talent.”

Dreesen began his career in the late 1960s as half of the comedy team Tim and Tom with actor Tim Reid, a barrier-breaking interracial duo. Reid later went on to star as Venus Flytrap in the 1978-82 sitcom WKRP in Cincinnati.

Dreesen continued as a stand-up comic, becoming a ubiquitous presence in the 1970s and ’80s (and thereafter), with more than 500 appearances on national television throughout his career. Perhaps most significantly, he made over 60 appearances on The Tonight Show with Johnny Carson and was subsequently a frequent guest on The Late Show with David Letterman. He occasionally guest hosted The Late Show in Letterman’s absence.

Considered one of the great “opening acts” in the business, Dreesen set the stage for numerous headliners like Liza Minnelli, Sammy Davis Jr., Frankie Avalon, Smokey Robinson, Tony Orlando, Gladys Knight and, most notably and for 13 years, his good friend Frank Sinatra.

Although complete information on survivors was not immediately available, the family statement said Dreesen “was a devoted father, brother, grandfather, friend, mentor, storyteller, and motivator. He gave generously of his time, supported countless charitable causes, and inspired others through his motivational speaking, his writing, and his personal example.”

The family, the statement continued, “asks for privacy at this time and is thankful for all the heartfelt condolences.”