Football anthems are chosen by fans - not the music industry. You'll hear these five songs in soccer stadiums around the world, though they originally had nothing to do with sports.
For true football fans, there's nothing more moving than swaying shoulder on shoulder with fellow fans in the stadium and shouting their team's anthem. Doing that the moment the ball drops into their opponent's goal is even better, of course - and better yet, after winning a tournament.
When the stadium joins in song, big, strong men get weak in the knees. Diehard fans could sing their club's songs in their sleep. Many of them, however, are shamelessly stolen from pop music. Celtic Glasgow fans, for example, have taken Depeche Mode's hit "Just Can't Get Enough" - and are very skilled at shouting it out in time with the beat.
The most famous football song of all time, of course, is "You'll Never Walk Alone," first adopted by FC Liverpool in England. The melody originally dates back to the Rogers and Hammerstein musical "Carousel," which was a story of love in turbulent times, a robbery and the death of a loved one. The hopeful song is featured at the end of the tragic musical.
From the theater to the stadium
The fact that this cheesy piece of music history made it into the tough world of British football can be attributed to the U.K. band Gerry & the Pacemakers. They released a cover version in 1963 and it shot to number one on the English charts. That same year, it was blasted through the loudspeakers in the Liverpool stadium for the first time.
A few weeks later, "You'll Never Walk Alone" was played again - and that was enough to get fans hooked. Liverpool faithfuls started regularly singing it to cheer their team on. The slow, gentle number would become one of the most unusual soccer anthems.
Because of its more solemn mood, "You'll Never Walk Alone" has created several goose-bump moments in soccer history. It was sung, for example at the FA Cup Finale in 1989, just a few weeks after the tragedy in Hillsborough Stadium, in which over 90 FC Liverpool fans were crushed to death in the crowd.
Gerry Mardsen from Gerry & the Pacemakers sang the track himself at Wembley Stadium. He told soccer magazine "11 Freunde" that he could "fall over dead" when the song swells through the stands: "I wouldn't be mad at God."
"You'll Never Walk Alone" quickly spread beyond Liverpool. In 2009, it was sung at the funeral for former German national goalkeeper Robert Enke, who committed suicide after suffering from depression. And just a few weeks ago, it was heard at the Europe League final between FC Liverpool and Borussia Dortmund. Some 45,000 fans joined in one song - a few tissues were certainly passed quietly through the rows.
Click through the picture gallery above for five songs that unexpectedly became soccer hits.