REVOLVER:You wouldn't be able to pick Neal Schon, Steve Perry and Steve Smith out of a line-up. But then, the only line-up those three would be in these days is a Forbesmagazine special on the most royalty cheques ever picked up for a single song. Back in 1981, when the Journey men wrote Don't Stop Believin', they were thrilled with its top 10 placing in the singles charts, but unaware they had just written a musical phenomenon.

In this download era, on each of the many occasions that their power ballad has featured in a film or been played at a major sports event, it’s climbed back up the charts. It’s now in the top 10 of most singles charts in the world. It just goes on and on and on and on.

If you presented Don’t Stop Believin’ at a songwriting class, you’d be laughed out of it. It has one of the strangest song structures ever, with the chorus not making an appearance until more than three-quarters of the way in.

Lyrically, it’s a poetically strained: Steve Perry sets up a narrative thread at the beginning – a small town girl and a city boy both taking a midnight train, but we never find out what happens to them. Instead, there are a series of exhortations to “don’t stop believing” and to “hold on to that feeling”. These kinds of banal aphorisms, so loved by politicians and TV personalities, mean nothing but sound positive and upbeat.

The song was always there as a minor rock classic over the years, but went straight to the front of the queue when it was used at the end of the final episode of The Sopranosthree years ago. For series creator David Chase, acquiring rights to the song was a real struggle.

"There was a lot of 'conversation' about my song choice," he says. "When I said Don't Stop Believin', people were going 'What? Oh my god!'. I said just give it a listen, and little by little, people started coming around."

Chase picked the song because it unfolds a bit like the final episode of The Sopranos: a gradual build up of tension with no real resolution. The line that goes "The movie never ends, it goes on and on and on and on" was crucial to Chase because it was his answer to all the speculation of how he would end the series.

Steve Perry, Journey's singer, was initially reluctant to give permission for the song to be used. He felt that it had built up a certain status over its previous 25 years or so and if it was used at such a dramatic stage of a prominent TV series, it would be inextricably linked to The Sopranosand not to Journey. "I was concerned," acknowledges Perry. "I was not excited about the possibility of the Soprano family being whacked to Don't Stop Believin'."

The band had no such hesitation when Simon Cowell approached them last year and asked them if he could use Don't Stop Believin'as the X Factorwinner's debut single (a song that reliably sells by the millions). It was a flat "No".

“Simon had contacted our management,” says guitarist Neal Schon. “He wanted to redo the song with a different arrangement. We listened to it. We declined.”

Cowell's master plan was ruined, he had to scrape around for a different song for Joe McElderry, and all he could come up with was the pedestrian Miley Cyrus song The Climb.However, Journey had no problems with the version of the song used on the US TV series Glee – they loved it and readily agreed.

By rights, though, this song should never had made its way out of the studio. On paper its structure is confused and fragmented: it opens with a piano riff, moves to the first verse, there’s a guitar arpeggio, a second verse, a pre-chorus, a guitar solo, a third verse, a repeat of the pre-chorus, another guitar solo, and then – at three minutes and 20 seconds – the actual chorus arrives.

Yet it worked magnificently. And it continues to do so. Don't Stop Believin'just goes on and on and on and on.