A year shy of a quarter of a century has passed since 'This is Spinal Tap' was released. In that time it has entered film folklore to become one of - if not THE - funniest film of all time. Taking a satirical look at the world of heavy duty rock n' roll, the movie continually flirts with genius as we follow the sights, the sounds & the smells of life on the road with the fictional rock band, Spinal Tap.

In a much-copied-but-never-bettered mock-documentary (or, if you will, mockumentary) style, director Rob Reiner teases out virtuoso performances & improvisational comedy gold from both the main players & the superb supporting cast.

Harry Shearer, Christopher Guest & Michael McKean inhabit their musical alter-egos to perfection, as the trio of axe-men struggle to come to terms with the threatened extinction of rock-dinosaurs like themselves. However, their child-like enthusiasm ('I envy us!') for all things Tap keeps the viewer forever on their side, willing the band to succeed in promoting their new album 'Smell the Glove', despite apparently entering the twilight of their career.

Even though much of the script is ad-libbed, there isn't an ounce of fat to be found. Repeated viewing rewards richly, as each scene contains so much exquisite detail that it would be criminal to watch just once.

At times, it's hard to believe the film is a spoof. The semi-mythical tales of life on the road from bands like Led Zeppelin & Black Sabbath seem to inhabit every pore of the movie. Characters & situations, whilst being achingly funny, are so believable that you just know many scenarios are based more on fact than fiction. And yet the film never succumbs to cruelty or easy laughs in its parody of the life of an ageing rock band - despite its inherent satire, 'This is Spinal Tap' is a charming, life affirming tale.

Perhaps surprisingly, the actual music is, unlike the glove, not to be sniffed at. Self-penned numbers like 'Stonehenge', 'Big Bottom' & 'Hell Hole' sound disturbingly authentic, & simply add to the impression that every aspect of the movie has been lovingly & carefully composed.

Guest, Shearer & McKean have gone on to achieve further success in films of a similar ilk like 'A Mighty Wind' & 'Best in Show', whilst Shearer is regular contributor to The Simpsons, voicing Principal Skinner & Mr Burns among many others. However, for me, 'This is Spinal Tap' is by far their crowning achievement, & is a film that has & will continue to stand the test of time.

Paving the way for The Rutles & later shows like The Office & Alan Partridge, 'This is Spinal Tap' has become the benchmark by which all other spoofs, reality satires & mock-documentaries are measured.

Such a film deserves a decent release, & the 2 Disc DVD doesn't disappoint. Packed with a treasure trove of extras & special features, it's a delight for fans & new-comers alike.

'This is Spinal Tap' is, in my opinion, the greatest comedy film of all time. If you've never seen it or don't own a copy, I urge you to beg, borrow or buy it! You'll be so very glad you did...

And when you watch it, make sure you turn the volume up to eleven...