PRESS ASSOCIATION -- Spoof music documentary This Is Spinal Tap has been ranked the greatest comedy movie of all time by experts.

The 1984 film, featuring a cast of unknowns who made much of it up on the spot, triumphed in a poll for Time Out magazine ahead of Airplane! and Life Of Brian.

A panel of comedy stars including Dan Aykroyd, Jackie Mason, Stephen Merchant and Jack Whitehall compiled the top 100.

Mockumentary Spinal Tap was released to little fanfare while some viewers were convinced the group - which had a knack of losing drummers in freak accidents - were a genuine band.

Word of mouth about the film, starring Michael McKean, Christopher Guest and Harry Shearer, helped it to become a sleeper hit.

DO YOU AGREE WITH THE STARS ABOUT THE COMIC VALUE OF SPINAL TAP? LET US KNOW YOUR THOUGHTS BELOW.

To master their characters the band played several shows, even supporting heavy metal band Iron Butterfly. And ironically, some Tap songs were later adopted by other bands - the hard rock act Soundgarden would regularly perform the track Big Bottom.

The film's deadpan lines - such as "It's such a fine line between stupid and clever" and "What's wrong with being sexy" - have had an enduring appeal.

Time Out film critic David Jenkins said: "It's sublimely funny and sharp - a comedy built for the long haul which matures with each viewing.

"It's so perfectly constructed and performed, the characters so rich and realistic, that it's initially a challenge to determine the dividing line between reality and fiction."