Gilmour has been playing since he was 9. "I was quite shy, closed in. It's classic, isn't it, your psychiatrist will tell you, that's how I release it, through music." He has an elegant vocal style, smooth and precise with a quality of dreamy yearning. "I love singing. I have spent as much of my life trying to improve my singing as I have practising guitar." But it is his extraordinary playing with its expressive, melodic, slow-burn style for which he is celebrated.
"It's a magical thing, the guitar," he says. "It allows you to be the whole band in one, to play rhythm and melody, sing over the top. And as an instrument for solos, you can bend notes, draw emotional content out of tiny movements, vibratos and tonal things, which even a piano can't do."
His playing has changed over the years. When Gilmour joined Pink Floyd in 1967, he was influenced by the experimental psychedelic daring of Floyd's tragic original frontman Syd Barrett. "I still want to explore, but I'm not as brave as I was then. I play safer now," says Gilmour. "You had to go through bad stuff to get to the good. Now I want it all to be good."
His new album, Rattle That Lock, is the strongest of his four solo efforts, combining the epic vistas of Floyd with the emotional intimacy of 2006's On an Island. Never a prolific lyricist, he has again collaborated with his wife, novelist Polly Samson. "I think this album is her best work," he says.
Last year, Gilmour and Floyd drummer Nick Mason released Endless River, a largely instrumental and apparently final Pink Floyd album assembled from sessions with late keyboard player Rick Wright. Gilmour accepts that it doesn't have "the grand theme" of Floyd's finest work. "Yes, it is lacking, but who cares?" he shrugs.
Although the classic line-up made an appearance at Live 8 in 2005 and Gilmour has occasionally got together on stage with old colleague, bassist and sometime antagonist Roger Waters, he has no interest in a reunion.
"Rick's dead. Roger and I don't particularly get along. We still talk. It's better than it has been. But it wouldn't work. Roger and I have outgrown each other, and it would be impossible for us to work together on any realistic basis."
Life for Gilmour has a much wider scope than his career. "I am not dominated by music every second of every day, which I was in my 20s and 30s. There are children, Polly is writing. I can't relate now to the dedication and religious fervour of youth. But something's lost and something's gained in living every day, as Joni Mitchell would say."
"I feel very lucky. And I feel some guilt at the extraordinary disparities, the great unfairness of life. I'd love to see what happens in the future. But I'm not going to be around for it."
Gilmour laughs, only half joking when he concludes: "I'm a has-been. I'm a relic of history."
Who: David Gilmour, onetime voice and guitar of Pink Floyd
What: solo album Rattle That Lock
When: Out now
- TimeOut, Telegraph