Bo Diddly

Bo Diddley, the musical pioneer whose songs, such as "Who Do You Love?" and "Bo Diddley," melded rhythm and blues and rock 'n' roll through a distinctive thumping beat, has died. He was 79.

One cannot think of Bo Diddley without hearing his calling card: That primal, propulsive "Bo Diddley beat," one of the most easily identifiable -- and oft-imitated -- rhythms in rock-and-roll history.