Reformed rockers Led Zeppelin were convinced to stage a comeback after enjoying a "secret rehearsal" following almost 20 years apart.

The band is set to play a one-off reunion concert at London's O2 Arena on December 10, and guitarist Jimmy Page insists once the band got together again, performing as a group was a must.

He says, "We wanted to see how well we'd be playing together and once we played it was without doubt we wanted to do it."

And Page admits the band was surprised by fans' reactions to their comeback - with more than a million people applying for random allocation of the $250 tickets.

He adds, "We were pretty confident it would sell out on the first day but the demand was totally overwhelming. I don't think anyone expected that demand in their wildest dreams."

-Led Zeppelin Pictures

(This news article provided by World Entertainment News Network)