A key element to Pink Floyd's sound, both as a vocalist and instrumentalist, David Gilmour hasn't been a regular presence as a solo artist. Still, his occasional albums have tended to focus on the band's more accessible side, and always showcase his distinctive guitar voicings -- ensuring that they will resonate with fans. He has collaborated over the years with Paul McCartney, Pete Townshend, David Crosby and Graham Nash, while producing the Dream Academy and his former bandmate Syd Barrett, among others. Along the way, Gilmour's solo work has informed, and echoed, his career with Pink Floyd. The guitarist demoed a song for his 1978 self-titled debut that became Floyd's 'Comfortably Numb,' and also collaborated on that album with Roy Harper -- who sang 'Have a Cigar' on 1975's 'Wish You Were Here.' Gilmour's follow up 'About Face' was co-produced by Bob Ezrin, after he served in the same capacity for 'The Wall' sessions. 'On an Island' featured Rick Wright and Bob Klose, who'd both worked with Pink Floyd, as well.