Songfacts®:

• The closing track of Pink Floyd's The Endless River album, this is the only non-instrumental song on the record. The lyrics were written by David Gilmour's wife, Polly Samson.
• The song contains David Gilmour's first new Pink Floyd vocal in 20 years. It was recorded at Gilmour's home studio in Hove on England's south coast. "Both Phil and myself had been pushing David to get the lyric and get the vocal," co-producer Youth recalled to Uncut magazine. "Everyone around him was saying how he hates doing vocals, and he always l;eaves them to the last minute... He does this amazing thing when he's composing and gets a melody. He does this skat vocal. It is absolutely perfect. Apparently that's how he did 'Comfortably Numb.' I've never heard a singer skat a lead vocal so exact, with the right emotion and everything. So we had this skat vocal, and then we waited for Polly and David to come up with the lyrics."
  
  "David had come up with a concept that when he went into the chorus, he would go low and the backing singers would go an octave up from him," continued co-producer and long-time Floyd engineer Andy Jackson. "He's a big Leonard Cohen fan, and that's something Leonard does a lot. Because the studio was in his home, he'd try it every day until he got all the lines he wanted. He ended up just doing it alone. It had been a while since he sang, so he had to get his voice limbered up, a bit every day."
• Polly Sampson's lyrics are both a tribute to former keyboardist and founding member of Pink Floyd, Richard Wright and a description of the symbiosis that the band members had. Co-producer Phil Manzanera described it to Uncut as, "a comment on their methods of working over their full careers; it seemed like a fitting summation of the complexity of the music."
  
  Andy Jackson added: "It's about the dynamics of being in bands, which I've always thought of as Big Brother on wheels. You become best of friends and worst of enemies all the same time."
• London string quartet Escala played on the song. The all-female electronic string foursome were finalists on Britain's Got Talent in 2008.
• The Endless River became Amazon UK's most pre-ordered album of all time. The record overtook One Direction's 2013 set Midnight Memories to claim the title. Asked why he thought that happened, Gilmour told CNN: "I'm going to sound like a grumpy old man. Modern music, to me, is very formulaic."
  
  "My children, who are now in their late teens and in their twenties, all went through phases of thinking the Beatles were the greatest thing on the planet," he added. "There are an awful lot of young people who are searching back through older music for something real, or more original."
  
  "Maybe they're looking for something they're not getting; something that's not made quite so robotically."
  
  The record was broken a few weeks later when Take That's first release as a three piece, III, became the most pre-ordered album of all time on Amazon.co.uk.
• The video was directed by designer Po Powell who first members of the then fledgling Pink Floyd in 1960s Cambridge. Together with Storm Thorgerson they designed the band's album covers as well as creating the artwork for many other famous acts. The clip features footage shot near the remains of the Aral Sea on the Kazakhstan and Uzbekistan border. "A surreal image if ever I saw one," Powell told Rolling Stone, "and a shocking example of human mismanagement and one of the planet's worst environmental disasters… The river has shrunk to 10 percent of its original size, destroying the fishing industry and whole townships."