The death of Joseph Sater, 73, the co-founder of Cambridge’s Middle East nightclub and other arts venues, was confirmed Tuesday by brother Nabil Sater. The cause was believed to be a heart attack, Nabil Sater said through an intermediary.

When family couldn’t get hold of Joseph Sater on Monday at his Hollywood, Florida, home, they asked a building worker to check in on him. Family believes Joseph Sater did not suffer, the intermediary said.

The Middle East opened in 1969 as a restaurant featuring belly-dancing and music of the region where Joseph Sater was born Dec. 3, 1952. One weeknight each dedicated to jazz and blues. Under the guidance of promoter Billy Ruane, who died in 2010, it turned increasingly to rock, becoming a nationally known destination. “Musically I loved it,” Joseph Sater said in an August 2018 interview. “When you brought the rock in, you took the tablecloth out.”

Over time The Middle East grew, becoming a complex of adjoining restaurants, bars and stages – ZuZu and Sonia in Cambridge – that filled daily with art, music and conviviality. The Saters also had properties elsewhere: The Firehouse in Allston and, for 13 years ending in 2021, an Armory building they refurbished in Somerville.

Local acts, midrange touring bands and global stars all performed at The Middle East, from The Sun Ra Arkestra and Dick Dale to Neko Case, The Flaming Lips and Modest Mouse.

“The Middle East has become the heart and soul of Central Square. The Saters have run that corner at Brookline Street and Massachusetts Avenue like the living room of their home – where guests come in and feel welcome and invited,” said Michael Monestime, executive director of the Central Square Business Improvement District, in January 2018. The quote was given in an interview with this reporter that was used in a story by this reporter published in Cambridge Day.

“The Sater family has been a real anchor in Central Square for decades.  They are open-hearted and sincerely compassionate and supportive of everyone in our community,” said Susan Fleischmann, former executive director of Cambridge Community Television, upon hearing the news of Joseph Sater’s death.

Parama Chattopadhyay, whose Out of the Blue art gallery was given a home in the Somerville Armory under the Saters, recalled meeting how she met Joseph Sater “when I came to the Middle East Restaurant 20 years ago, like just about every college kid across Camberville. Thousands of folk in Boston may consider him a best friend, and I am just one of those. But I revered my art uncle, was even a bit scared of him only because I never knew if I was making him proud, and I always looked to him for guidance and support. And he always made time.”

Clay Fernald, a musician and booker whose work at The Middle East began in 2001, was struck  on Tuesday by Sater’s ability to create community, whether it was nightly closeouts in which “all of his friends would come by to have some red wine with him at his table” or spontaneous parties such as when Barack Obama won the presidency – a night so packed that Fernald said he was still meeting people 10 years later he didn’t realize was there.

“What the Saters built at the Middle East” made it possible for generations of people to have entertainment and music careers, Fernald said, and all while “remaining independent.”

There were ups and downs, Fernald said. The family spent $7.1 million buying its property in Central Square in 2014 after a threat that the former landlord would sell it out from under them, and that caused financial pressures; the city of Somerville seized the Armory property under eminent domain laws after the Saters struggled during the Covid pandemic. Joseph Sater stepped away from management of The Middle East in August 2018 after a sexual assault allegation began hurting bookings at the club. The family denied the allegations.

He spent more time in Florida looking after other family interests and, Fernald said, “saving beach turtles – he found some abandoned turtles and worked with wildlife preservation down there on the beach to save them. So he was not only a friend to all the artists and musicians, but also a friend of animals.”

Sater visited Cambridge a few weeks ago, Fernald said.

“I just wish I could have hugged him a little bit longer when I say goodbye,” Fernald said.

Monestime said Tuesday that there would likely be a celebration of Sater’s life planned. Fernald said tributes were already pouring in.

This post will be updated. This post was updated to correct that a quote was given in a different year.