I am a huge fan of the rock documentary... or 'rockumentary' if you prefer (thanks, Spinal Tap).

They're generally quite different from stylish big-budget biopics, the majority of which rarely succeed. With a few exceptions, directed biopics can be risky or even risible. It's a tough job for an actor to play a living or recently deceased musician, some of whom have had a profound effect on the viewer.

The rock doc however is usually the truth, or something approaching it. These booze- and drug-addled chronicles take many shapes, and points are usually given for originality in a well-trodden, frequently covered genre. Take a look online, or watch BBC Four of an evening, and see how many are out there. From the detailed analysis of an artist's life with added personal anecdote and eye-watering secrets, to an emotive confessional that goes way beyond mere career peaks and troughs, they sometimes pinpoint stories of real tragedy or redemption.

After a well-received or critically acclaimed film, an artist can experience a genuine renaissance, such as 1970s troubadour Rodriguez after Searching For Sugar Man, or long overdue exposure like Canadian metal stalwarts Anvil. Usually they simply prove how important and influential an act is - leather-clad New York rockers Ramones in End Of The Century and unlucky punk survivors The Damned in Don't Fou Wish That We Were Dead come to mind.

Sometimes a soupcon of fabrication enters the fray as well. The Nick Cave film 20,000 Days On Earth is shot through with artistic licence during the dream-like, fictionalised 24 hours in the writer's life. And watch the Great Rock'n'Roll Swindle, where Malcolm McLaren was, shall we say, economical with the truth when telling the Sex Pistols story. Both are visionary, somewhat anarchic artefacts that take the viewer on an extraordinary journey.

As we dig deep, looking for unique and poignant stories to touch or enhance our own lives, films like these can be truly inspirational or at the very least spin a ripping yarn about a collection of wild, untamed, creative lives. For someone nonplussed by most modern celebrity, this is my world of juicy gossip, where the characters are actually eccentric and interesting. Some read Heat magazine or watch Big Brother; I like rock docs and biogs.

The Edinburgh International Film Festival (EIFF) kicks off once again this Wednesday with a selection that should pique the interest of music lovers out there. The most high profile film is Amy, about the troubled but extremely talented chanteuse Amy Winehouse. It premiered at Cannes and was hailed as a huge success, despite her own father's critical hollering. It seems his version of events differ slightly. This just adds to the intrigue.

Whether you own her records and enjoy the occasional song or not, this heart-rending story has been duly transformed into a commanding, insightful piece of filmmaking. There's a mix of stock from high-quality and state-of-the-art, through to the home-made and lo-fi, making it a personal, intimate albeit rather controversial piece.

Conceptual artist, label boss, author, KLF member and all-round prankster Bill Drummond is also the subject of a new film, Imagine Waking Up Tomorrow And All Music Has Disappeared, which also looks really fascinating. The elusive Scotsman has defied convention at every turn throughout his rich and varied career, leaving a dead sheep at the Brit Awards and burning a million pounds on the Isle of Jura being only two infamous examples. The film sheds a truthful, unguarded light on his life and work to date. Apparently he will take part in a special performance after the screening on Wednesday June 24...

Perhaps of most personal interest to me, being firmly lodged in the capital, is Big Gold Dream which documents Edinburgh's own largely overlooked underground within the halcyon era of late 1970s and early 1980s punk and post-punk. Having seen a sneaky preview copy, I can vouch for the visceral thrills and candid honesty therein.

Alongside the well-documented early lives of Orange Juice, Alan Horne and Postcard Records, here the previously untold story of Bob Last and his influential independent record label Fast Product, a precursor to the celebrated Rough Trade and Factory Records, takes centre stage.

Cult heroes such as The Rezillos. Scars, Fire Engines, Josef K and Associates finally get their moment in the sun, and rightly so, as Grant McPhee's long-awaited and dedicated film tracks down and interviews the key figures and main instigators. Always seen as the poor cousin to Glasgow's thriving, focused and successful indie scene, Auld Reekie now gets the historical recognition and focus it deserves.

It is fitting that the world premiere of such a film would be at the EIFF, and I only imagine that many of the survivors of that time will be in attendance to watch their thinner, younger, sexier selves. A selection of the musicians certainly will be, as tickets to the showing this Friday will include access to an exclusive gig afterwards featuring some of the talent on screen.

This is all folklore to me. I love being regaled with tales of derring-do and heroic, creative courage in the face of mediocrity and commercial pressure. Rock'n'roll, pop and art may be our last bastions of freedom in this day and age, and films like these are essentially introducing us to these bygone heroes and showing us behind the scenes. Long live the rockumentary!

Vic Galloway presents on BBC Radio Scotland at 9-11pm on Mondays and 11pm-1am on Thursdays, www.bbc.co.uk/radioscotland. Tomorrow he has FFS as guests plus BBC Introducing at the Quay highlights. Contact Vic at www.twitter.com/vicgalloway