Mullen died at Ventura County Medical Center, said his companion of 16 years, Kateri Butler, on Monday. The couple had been traveling through Santa Barbara and Ventura to celebrate his 60th birthday, which was Friday. 'The doctors are completely perplexed,' Butler said. 'They can't figure out why he had a stroke -- he had none of the indicators, his cholesterol was perfect. One of the neurologists summed it up best when he said, `Sometimes, your number is just up.' ' At the Masque, Mullen created an underground space that served as a crucible for musicians and fans who felt alienated from mainstream society. Anger, frustration and self-deprecating humor flowered in the assaultive music that had been roiling in New York and London as Los Angeles bands, including the Weirdos, the Germs, the Dils and the Screamers, turned up regularly at the Masque for some of their earliest performances. 'He was the first promoter of punk rock in this town,' said veteran promoter Paul Tollett of Goldenvoice Presents. 'Everything started with him.' Once word spread that a space had emerged that was hospitable to punk, which at the time was a frequent target of law enforcement, more bands quickly followed. The Masque became home to X, the Go-Go's, the Dickies, the Plugz, the Flesh Eaters and many more. Mullen, who had worked as a journalist in England before moving to the U.S., remained humble about his role. 'For the record, I never claimed to have `started punk in L.A.',' Mullen wrote in his book 'Live at the Masque: Nightmare in Punk Alley,' published in 2007. 'I'd prefer the Masque epitaph to be `Where the SoCal scene originally came together'.' Brendan Charles Mullen was born Oct. 9, 1949, in Paisley, Scotland, outside Glasgow, to a Scottish father who loved musical theater and an Irish mother. The family moved to Manchester, England, when he was about 8 years old. Mullen also spent time in London, writing about music for British magazines before moving to the U.S. in the mid-1970s when he was a teenager. He toured the country for a time before settling in Los Angeles in 1974. By 1977, an amateur musician himself, Mullen went looking for a place where he could jam with like-minded players. 'I was tooling off Hollywood Boulevard searching for a cheap space when I spotted an open doorway in a grimy alley,' he wrote in 'Live at the Masque.' '(I) went down a flight of greasy stone stairs and, just like Theseus stalking the Minotaur, dragged string and some old hose pipe behind me, fearful of not being able to find the way back out from this pitch-black, seemingly endless labyrinth of doors, corridors, passageways, stairwells, tunnels, and musty odd-shaped rooms.' He had wanted only a room to practice in, but the building's owner offered him the entire 10,000-square-foot basement for $850 a month, allowing him to set up numerous rehearsal spaces for the burgeoning punk music community. The original Masque ran until 1978, when the fire marshal cited the club for violations and the building's owner, wary of the controversy surrounding it, sued Mullen to end the lease. Bands came to his aid with two nights of benefit concerts to raise money to pay legal fees -- shows that culminated in rioting. Mullen kept the club's spirit alive through a string of 'Masque Presents' concerts staged at a consortium of other rooms around the region. He briefly opened what he called 'The Other Masque' at another location from 1979-80. After the Masque closed, he worked for more than a decade at Club Lingerie, which became celebrated for Mullen's eclectic bookings that ran from punk and pop to jazz and blues, as well as the first West Coast appearances by several New York hip-hop acts. He also booked a wider range of performances at the Variety Arts Center downtown in the 1980s. 'He really changed the face of club booking with the very eclectic mix he had, all sorts of different people performing there from the Red Hot Chili Peppers to Sun Ra to old blues musicians like Big Mama Thornton,' Butler said. 'He had wonderfully eclectic taste in music. He could love Sun Ra as much as he loved the Germs.' In recent years, he had focused on writing books documenting the music scene in which he had been so instrumental: 'We Got the Neutron Bomb: The Untold Story of L.A. Punk,' published in 2001; 'Lexicon Devil: The Fast Times and Short Live of Darby Crash and the Germs,' and 'Live at the Masque.' Butler said that Mullen had just started working toward U.S. citizenship after living here for so many years. 'He loved L.A. and he loved the United States,' she said. 'He loved it over here, coming from a stratified place like England to the U.S., a place of so many opportunities -- especially at the time he came, in the `70s, which was a pretty grim time in England.' In addition to Butler, Mullen is survived by three sisters: Pauline Mullen, Una Earley and Nuala Rainford. 