The Isley Brothers

It doesn't seem possible that the same band can have cut R&B classics in the '50s and '60s, pioneered a new rock-funk fusion in the '70s, and still be breaking boundaries with a blend of soul and hip-hop in the 21st century. But it's true, and these Isley classics provide the evidence.

Two generations of Isleys have lent their talents to the group's just-short-of-50-year career. But the man at the heart of the story has always been Ronald Isley — one of the greatest soul singers of all time. Check out his soul-soaked cries on these gems.

Whether it's the vocal combination of Ronnie, Rudolph and O'Kelly, or the instrumental power of little brothers Ernie and Marvin and cousin Chris Jasper, the Isleys have the ability to handle everything from delicate ballads to full-on funk workouts. American music doesn't get much better than these lesser-known gems.

Nobody's talking, but The Isley Brothers might have put the smooth in the notion of smooth grooves. They definitively introduced simmer to white-bread slices like "Summer Breeze," while morphing a mid-tempo jam like "For the Love of You" into a do-it-all-night anthem. At the same time, part of the "a" in funk-ay belongs to them, too. Try "It's Your Thing" or the rock fusion of "That Lady" on for size. They fit perfectly.