GENEVA — Blues-rock legend Johnny Winter came out of Beaumont in the late 1960s with a memorable look — tattooed arms churning out lightning-fast guitar riffs and striking long white hair flowing from under his cowboy hat — and a memorable sound.After playing at Woodstock, he became one of the most popular live acts of the early 1970s. The crowds were dazzled by the speed — and volume — of his guitar playing, which had its roots in urban blues but incorporated elements of rock ’n’ roll. Mr. Winter was a leading light among the white blues guitar players, including Eric Clapton and another Texan, the late Stevie Ray Vaughan, who followed in the footsteps of the earlier Chicago blues masters. He idolized Muddy Waters — and got a chance to produce some of the blues legend’s more popular albums. Rolling Stone magazine named Mr. Winter one of the top 100 guitarists of all time.Mr. Winter had been on an extensive tour this year to celebrate his 70th birthday. He died Wednesday at a hotel just outside Zurich, said his representative, Carla Parisi.The cause of death was unclear and authorities have ordered an autopsy, a Zurich police spokeswoman said. Investigators are mainly looking at “medical causes” and there is no indication that anyone else was involved, she said. His last performance was Saturday at the Lovely Days Festival in Wiesen, Austria. He had recently announced that he would follow up his 2011 album Roots with a new studio album, Step Back, in September. It was to feature collaborators such as Eric Clapton, Ben Harper, Joe Perry, Dr. John and Joe Bonamassa. John Dawson Winter III was born Feb. 23, 1944, in Mississippi. His family moved to Beaumont when he was an infant. He was the older brother of Edgar Winter, who, like him, was an albino, and rose to musical fame with the Edgar Winter Group. “Made my first record when I was 15, started playing clubs when I was 15. Started drinking and smoking when I was 15. Sex when I was 15. Fifteen was a big year for me,” Mr. Winter recalled with a laugh in a documentary released this year, Johnny Winter: Down & Dirty. “I love playing guitar. It’s the only thing I’ve ever really been great at,” he said. His career received a big boost early on when Rolling Stone singled him out as one of the best blues guitarists on the Texas scene. This helped secure a substantial recording contract from Columbia Records in 1969 that led to the appearance at the Woodstock festival and gave him a wide following among college students and young blues fans. Mr. Winter performed often with singer Janis Joplin, who grew up in nearby Port Arthur. Heroin addiction, alcoholism and prescription medication abuse derailed his career in the ’80s and ’90s. “The real legacy of Johnny Winter is that he brought the blues to an audience in tie-dye that might otherwise have neglected the entire genre — and his timely work producing Muddy Waters only deepened that contribution,” said music writer Fred Schruers.