For those of us who first came to music in the '70s, Horslips, Thin Lizzy and Rory Gallagher loomed, as John Montague wrote, like dolmens around our childhood. Old enough to experience the odd Almost Famous moment with our big brothers' album collections, but still too young to buy our own (let alone attend a real live rock concert), we marvelled at the long-haired titans on the gatefold sleeves of Dancehall Sweethearts and Live And Dangerous, giant figures who seemed as unknowable as Tuatha De Danann.

But the old gods fell into decline. By the time we caught Lizzy on their farewell tour in the RDS in 1983, Phil Lynott was in a bad way, and his band turned in a performance that was slick but uninspired. Horslips split after the Belfast Gigs. The guard changed. U2 and The Pogues and The Waterboys dominated the concert halls. By the late 80s, Public Enemy, Nick Cave and The Pixies made oldies like 'The Boys Are Back In Town' and 'Dearg Doom' sound like the ravings of men from another age. We grew weary and suspicious of the Irish rock heritage park nostalgia racket and renounced holy relics like Jailbreak and The Táin. Historically significant, we sniffed, but haven’t dated well.
Then certain breezes gave occasional cause to reconsider. Horslips' cameo in Pat McCabe’s The Dead School. Rollins in full Lizzy evangelical mode at his stand-up shows. Maurice Linnane’s excellent Dancehall Sweethearts documentary from a few years back.
Just this week, we watched Ian Thuillier’s documentary Ghost Blues and were once again knocked backwards by the power and fire of Rory Gallagher. We remembered seeing him in 1983, blistering the paint from the walls of a Kilkenny hotel ballroom with a two and a half hour show (one-fifth of it devoted to an acoustic set). Thuillier's film, featuring contributions from Bob Geldof, Cameron Crowe, The Edge, Slash, Bill Wyman and James Dean Bradfield, was neither sentimental nor hagiographic, but an honest portrait of a journeyman who exhibited an almost Franciscan devotion to his vocation. Gallagher was a stubborn and uncompromising electric blues purist who gave no ground when it came to his art, and held nothing back when it came to his craft.

Ghost Blues is viewable on the RTE Player archives until July 1. Take a look.