ZZ Top drummer Frank Beard was remembered at a private funeral service in Texas … with family, close friends, bandmates, and crew members gathering to honor the rock legend … TMZ has learned.

A memorial flyer for the service, obtained by TMZ, says the funeral was held Tuesday afternoon at Forest Park Southwest. The invitation describes the event as a celebration of Frank’s life.

We’re told the service was intentionally intimate … with only family, friends, his ZZ Top bandmates and members of the band’s crew in attendance.

As we previously reported, Frank died August 17 at 77. The Fort Bend County Medical Examiner confirmed Frank passed away at his Texas ranch with family by his side, after a stay in hospice.

He was the longtime drummer for the Texas rock trio, joining Billy Gibbons and Dusty Hill in the band’s classic lineup and helping power hits including “La Grange,” “Tush” and “Sharp Dressed Man.”

Frank’s was the lone remaining member of ZZ Top’s iconic original trio.

As we reported, Frank’s health forced ZZ Top to cancel its August 5 concert at the Hollywood Bowl … just weeks before he died.