Maglieri died Thursday morning "surrounded by loved ones," his family said in a statement. No cause of death was given.
For decades he operated two of Hollywood's most venerable and legendary Sunset Strip nightclubs - the Whiskey A Go Go and the Rainbow Bar & Grill.
"Rest In Peace Mario Maglieri King of The Sunset Strip," the marquee over the Whiskey proclaimed Friday.
It was at the Whiskey that the Doors found a following as the house band in the 1960s. Over the years Led Zeppelin, the Police, Van Halen and literally hundreds of other acts spanning generations have played there.
The Beatles dropped by for a visit during their first U.S. tour in 1964. George Harrison, annoyed by a paparazzi, threw a drink at him, hitting actress Mamie Van Doren instead.
At the Rainbow, Maglieri would keep many of his musicians in booze and food, occasionally having to throw one or more of them out when they caused too much trouble.
"The rowdiest? Oh, Guns N' Roses! I had to put them out I don't know how many times," he told the Los Angeles Times in 1993. "They're good guys, but they get out of hand."
Born Feb. 7, 1924, in Seppino, Italy, Mario Mikeal Maglieri moved to the United States with his family at age 4.
He ran restaurants and clubs in Chicago for a few years before moving to Los Angeles in the 1960s to manage the Whiskey, eventually taking it over. A few years later, he and partners took over a nearby Sunset Strip restaurant and renamed it the Rainbow.
It was a heady time on the Strip in those early years, one punctuated by up-and-coming young musicians and their groupies, many living in nearby Laurel Canyon. There was an abundance of drugs and alcohol as well, although Maglieri said he never partook of the former.
"I'm 70 years old, and I've never smoked a joint in my life," he told the Times in 1993. "People ask me and I tell them, 'Dope is for dopes.' People want to fight me on that, I'll fight them. I've seen too many lives destroyed by drugs."
He said he bought Janis Joplin a bottle of her favorite whiskey, Southern Comfort, three days before she died of a drug overdose in 1970. He also spent a good deal of time trying to talk Morrison into cutting back on his substance abuse before he died in 1971.
"He was a good boy. It's too bad I couldn't straighten him out, because I tried awful hard," he said.
But he also recalled numerous good times, among them talking politics with John Lennon in the parking lot and watching members of Led Zeppelin have fun.
"Every time they were in town, they'd party in the middle booth," he said. "And them guys know how to party."
He is survived by his wife, Scarlett; a son, Mikeal; and three grandchildren.
A public memorial is scheduled May 28 at the Rainbow.
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