Linda Ronstadt is an American singer of Mexican/German descent who was a highly successful international pop star during the 1970s and 1980s. She's withdrawn from the spotlight a bit in recent years and records more Latin folk music than pop/rock these days, but she's always had a great voice. Here are two of her classics:
Linda's hit rendition of Buddy Holly's "It's So Easy"
...and her wonderful rendition of Roy Orbison's "Blue Bayou"