Alex Ligertwood, the Scottish musician best known for a number of stints as the lead singer of Santana, has passed away. As TMZ points out , Ligertwood's daughter announced his passing in a social media post . Ligertwood died in his sleep at home in Santa Monica on Saturday. No cause of death has been reported. He was 79. Alex Ligertwood grew up in Glasgow and sang for local bands as far back as the '50s skiffle craze. He had a brief stint singing for the Jeff Beck group in 1970, and he joined Santana in 1979. Ligertwood had five separate stints with Santana between 1979 and 1994. He sang on their commercially successful albums Marathon and Zebop! and on hits like their versions of Russ Ballard's "Winning" and Ian Thomas' "Hold On." Ligertwood was also Santana's singer when they played at Live Aid in 1985. Ligertwood sang for a number of other bands over the years. Until very recently, he was touring with a group called Icons Of Classic Rock, and he played his final show just two weeks ago.…