This song is about how time can slip by, but many people do not realize it until it is too late. Roger Waters got the idea when he realized he was no longer preparing for anything in life, but was right in the middle of it. He had just turned 28.
When the band came up with the concept for the album, the idea was to explore the pressures of life throughout the songs. This song takes on the topic of mortality.
The song starts with layers of clock noises that were put together by their engineer, Alan Parsons. Each clock was recorded separately at an antiques store, and the band blended them together. Parsons wanted to use the clocks to demonstrate a new quadraphonic sound system, but they ended up using it to open the song instead. (thanks, Joe - Piscataway, NJ)
This was the only song on Dark Side Of The Moon that all four members received a writing credit for.
The Dark Side Of The Moon album has sold over 34 million copies and was on the US charts for 741 consecutive weeks (14 years). It entered the charts in March, 1973, and didn't leave until October, 1988. Even after it fell off, it continued to sell thousands of copies every week.
On their 1973 tour, they played this just after a 4-foot model plane was released from the back of the venue, crashing into the stage and exploding. Floyd always used lots of visual effects at their shows, and had the money to make them very elaborate on this tour.
The band played this live long before it was released. They played the whole album in February, 1972 at the Rainbow Theater in London, over a year before it came out.
This contains a reprise back to the rhythm of "Breathe," which appears two songs earlier on Dark Side of the Moon. "On The Run", an instrumental, is in between. (thanks, Matt - Russell Springs, KY)
At the time of recording only a few tom-tom drums were available for the intro. To get the right mix and sound, the band had to tune each drum after hitting it, record it, and then blend and mix into a finalized percussion track. This was a time intensive process. (thanks, Joe - Piscataway, NJ)
The sound at the begining of the song is made by Waters' bass. (thanks, Marcus - Wooster, OH)
In 1998, Dark Side Of The Moon was certified 15x Platinum, meaning it had sold more than 15,000,000 copies. In 2003, the album was re-released on vinyl and has sold steadily in that format. (thanks, Bertrand - Paris, France)