So the legendary British rockers "Spinal Tap" are on the comeback trail. After a dry spell in the USA, they determine to take their provocative new album and their film-faking fan "Marty" (Rob Reiner) and re-establish themselves as superstars. "Marty" has access to all aspects of their activities as he makes the ultimate fly-on-the-wall documentary depicting the ups and downs, warts and all, of this band of musicians who epitomise just about everything good, bad and excessive in the industry at which this film takes an entertaining swipe. Interspersed with some decently staged rock numbers that could easily have been seen on MTV, we are exposed to the extremes of venality and avarice, some completely bonkers lyrics and their gradual realisation that the grand stadium days are maybe long gone, now. The bickering always stays on the amiable side of toxic, but squabbles about their racy album cover being banned in Walmart, their shrinking appeal narrowed now to just to stoned-out students and their own peccadilloes deliver an enjoyably authentic looking and frequently quite funnily written analysis of life on the downward side of the showbiz mountain - and it's quite scathing of those who make a living out of it with little or no talent but a solid belief in what they see in the mirror. This is British sarcasm and irony at it's cinematic best, disguised in a faux environment that even now, after forty years, is still often laugh out loud.