ROCK FANS WATCHING this year's Super Bowl likely experienced a jolt of unexpected delight when they caught a glimpse of one of their own — Nuno Bettencourt, ever-present Washburn N4 in hand — performing alongside Rihanna during her halftime-show extravaganza. But while his screen time was exceedingly brief — “about 1.5 milliseconds,” he jokes — Bettencourt's partnership with the international pop superstar, as many now know, stretches back more than a decade.
If some fans believe it to be a strange place for one of hard rock's most
