Who – or what – was Garech Browne? It’s hard for the people who knew him to reach a consensus, although Last Days at Luggala (RTÉ One, Wednesday, 9.35pm) opens bidding with “patron of the arts and traditional music”, which is how the man would have liked it.

Other attempts are more colourful, such as Grey Gowrie’s description of the branch of the Guinness dynasty to which Brown belonged as a family of “interesting eccentrics”. This included his mother, Oonagh, who repaired to the humongous, serene Luggala estate, in Co Wicklow (a wedding present from her father, Ernest Guinness), following the demise of her second marriage, with her young children Garech and Tara. Despite a brief, amusing, unsuccessful attempt at school, Garech never seemed to leave the place.

Nobody in Mick Mahon’s film uses the word ethnomusicologist, although the incongruous “Anglo-Irish toff” with flowing hair and Cúchulainn’s winter wardrobe who travelled the country recording jigs, reels and sean-nós was clearly that. These were melodies, says Bono (whom Browne switched on to trad), “that would never be heard again if not recorded. This was priceless stuff.”

But the most compelling description we get of Browne is from the singer Dolly McMahon: “He was just a person who collected people, if you like.” The idea of a collector – committed, compulsive, forever incomplete – is hard to dislodge, here seen amid a clutter of musicians, dazed models and, somewhere between the two, Mick Jagger.

The weirder aspects of Browne’s character are reflected in the film-maker John Boorman’s daffy 1970s film in which he has Browne levitate, in awkward ecstasy, hearing the uilleann pipes of Paddy Moloney. (If there was anything harder on offer at these parties than champagne, or Moloney, it isn’t mentioned.)

It falls to Gowrie to describe how profligate Browne’s living became: “His burn rate was colossal,” he remembers, as Browne’s spending climbed to the millions, finally, at the risk of destitution.

“We’re skirting around the fact that he was an alcoholic,” Gowrie solemnly adds later, “and that is debilitating.”

Out of the blue, Browne phoned Paul Howard with advice: if he ever smoked opium, do it in China, where they know how to prepare it. ‘That’s all,’ Browne finished. ‘Toodle-pip’ On that point nobody disagrees, and it moves to a reflection on Browne’s loneliness. His marriage, to Princess Harshad Purna Devi, survived, Boorman says, “because they never met each other”. And after the parties, the writer Paul Howard points out, “everyone goes home”. Even Mick Jagger.

Mahon’s film absorbs some of the collector’s impulse, too, stuffed with archive material, photographs, record sleeves, Bono, you name it, leaving little room to go deeper into Browne’s character or his legacy.