Bo Diddley, whose role in the invention of rock and roll as we know it is matched only by Chuck Berry, died today of heart failure. He was 79. His innovations included flashy custom-built electric guitars and, obviously, the famous Bo Diddley beat (though, as Robert Christgau once noted, "there are as many diddleybeats as there are Diddley songs"). He was also an emotive, inspired singer. Here's one of my fave Diddley performances, of Willie Dixon's "You Can't Judge a Book By Looking at the Cover."