 Spanning the globe, this is the triathlon of rock and roll, the endurance champs on the chart based on tabulations of their Billboard Top 40 hits. Now we're up to a five-time Grammy winner who says she never wanted to be a performer. With her master's degree in education, she just wanted to teach music. Instead, she's taught us how it's done on the charts with hits spanning three decades, from Do You Know the Way to San Jose to Then Came You to That's What Friends Are For.