The Liverpool club credited with launching the career of The Beatles celebrated its 50th anniversary with a 13-hour party.
The club was demolished in 1973 but then rebuilt 10 years later
The Beatles played hundreds of gigs at the Cavern Club between 1961 and 1963.
It was demolished in 1973 but reopened 10 years later on part of the same site using reclaimed bricks from the original building.
A piece of public art, showing the site of the doorway to the original club, was unveiled as part of the events.
Cavern spokesman Dave Jones said the invitation-only party would reflect all the bands which had played at the basement club over the past 50 years.
"The Merseysippi jazz band, who played the first night of the club in 1957, are kicking off the gig and then we have around 30 bands performing," he said.
"We also have more contemporary bands to reflect the history of the club over the years.
"It is a celebration of the club as a live music venue from the 1950s through to today."