Bob Klose was the original lead guitarist of Pink Floyd before Syd Barrett.

Bob Klose. He played in the early incarnation of the band (then called The Tea Set or Sigma 6) alongside Waters, Wright, and Mason. Klose was a skilled blues guitarist, but he left in 1965 because he wanted to study architecture, not chase rock stardom. Syd Barrett replaced him, and the rest is history.

If Klose had stayed, Pink Floyd would have sounded very different — probably more like a blues cover band than the psych-rock pioneers we know.