"Time" is the fourth track from the English progressive rock band Pink Floyd's 1973 album The Dark Side of the Moon, and the only song on the album credited to all four members of the band, though the lyrics were written by Roger Waters. It is the final Pink Floyd song credited to all four members and the last to feature Richard Wright on lead vocals until "Wearing the Inside Out" on The Division Bell. This song is about how time can slip by, but many people do not realise it until it is too late. Roger Waters got the idea when he realised he was no longer preparing for anything in life, but was right in the middle of it. He has described this realisation taking place at ages 28 and 29 in various interviews. It is noted for its long introductory passage of clocks chiming and alarms ringing, recorded as a quadrophonic test by Alan Parsons, not specifically for the album.

Time is in the key of F-sharp minor. Each clock at the beginning of the song was recorded separately in an antiques store. This is followed by a two-minute passage dominated by Nick Mason's drum solo, with rototoms and backgrounded by a tick-tock sound created by Roger Waters picking two muted strings on his bass. With David Gilmour singing lead on the verses and with Richard Wright singing lead on the bridges and with female singers and Gilmour providing backup vocals, the song's lyrics deal with Roger Waters' realization that life was not about preparing yourself for what happens next, but about grabbing control of your own destiny.

He (Alan Parsons) had just recently before we did that album gone out with a whole set of equipment and had recorded all these clocks in a clock shop. And we were doing the song Time, and he said "Listen, I just did all these things, I did all these clocks," and so we wheeled out his tape and listened to it and said "Great! Stick it on!" And that, actually, is Alan Parsons' idea.

...
Wikipedia