The remaining members of the Who — Pete Townshend and Roger Daltrey — this week kicked off what’s being called the band’s final tour. (We’ve heard that before, but maybe it’s true this time.) The Who Hits 50! tour won’t pull into Boston until Oct. 29 at TD Garden, but Daltrey credits MGH surgeon Steven Zeitels with enabling him to be on the road at all. “My voice is fine. I’m quite lucky that I met the genius Dr. Steven Zeitels up in Boston,” he says in an interview with Rolling Stone. “My vocal cords are better now than they’ve ever been!” Zeitels has salvaged the voices of many well-known singers, including Julie Andrews, Steven Tyler, and Adele.