Band biographer claims that DJs only played the now classic song because it was the 'perfect length' for a cigarette break

Was the secret to Stairway to Heaven's success the fact that it gave DJs the chance to nip out for a cigarette? That's the theory of Led Zeppelin biographer Charles R Cross, who claims that 100 radio presenters "literally ... swore" that they aired the now classic tune because it was the "perfect length" for a cigarette break.

"The song became successful by accident," Cross told the New York Post. "[I] had 100 DJs swear to me that they only played the song because they needed a long break to go and smoke a cigarette. If it had been a minute shorter, you couldn't have smoked a full cigarette. If it had been a minute longer, it would have been too long."

Although it was never released as a single, Stairway to Heaven is now one of radio's most broadcast songs. This is, Cross argues, a blessing and a curse for the now defunct band. While guitarist Jimmy Page loves playing the ballad's crescendo, singer Robert Plant now says he "loathes" it. "Page's love of the tune seemed to go in inverse proportion to Plant's hate," Cross said.

In fact, Plant's dislike of Stairway to Heaven may be one of the major obstacles for a Led Zeppelin reunion. Cross says Plant simply doesn't want to sing it every night. Before reuniting at New York's Madison Square Garden in 1988, the band had a row about whether it should appear on the set list. Almost two decades later, at Led Zeppelin's one-off concert at London's O2 Arena, Stairway to Heaven did make the cut – but Plant allegedly insisted that it appear in the middle of the set, not as a finale; and that Page restrain himself from turning the song into an even more epic solo-filled noodle.

Cross's new book, Led Zeppelin: Shadows Taller Than Our Souls, was published in October.