DAVID CASSIDY: THE LAST SESSION, ON A&E

David Cassidy was the sort of male pop star that comes along once every decade or so - the sort of non-threatening man-boy who made the hearts of prepubescent girls pound like sledgehammers, the sort of entertainer who floats along on a river of hype - and then evaporates. This says more about the farcical nature of celebrity than it does about the guy, who was actually a lover of heavy rock and blues, could play the guitar fairly well and, despite the plastic trappings of a TV show like The Partridge Family, had a voice any pop singer would envy. Sure, his kissable face appeared on lunch boxes and on the splash pages of articles like 'What's it like to go on a date with David?' but if we can believe David Cassidy, The Last Session (already aired on A&E, but available on the A&E app) he was a doomed soul, a sad, vulnerable alcoholic who seemed plucked from the most tragic pages of Irish literature, complete with an aloof father he could never please.

Early on we meet Cassidy shortly before his death in 2017. He's alarmingly frail, looking much older than his 67 years. He's in a Chicago recording studio, struggling to put vocals on an album of old jazz standards. The project is a tribute to his father, Broadway singer and TV actor Jack Cassidy, but David can't remember lyrics, and the voice that once soared across the AM radio dial is down to a tired croak. Then we see him in a hospital, undergoing a brain scan because he fears he's suffering from dementia. When asked about his history of drinking, he gives vague answers. Maybe he quit five years ago. Maybe it was just a few months ago. All he knows is that something is wrong. It doesn't happen all the time, he says, but sometimes he forgets where is is. He sounds glib, but exhausted. He turns his sad life into amusing patter, telling a brain specialist that he used to drink enough to kill a man.

Much of this documentary is the traditional tale of a fellow who seemed to have everything, only to lose it all. We hear from Alice Cooper,  Kim Carnes, Danny Bonaduce, and others, including a former editor of Tiger Beat who recalls Cassidy hiding from her rather than submitting to another stupid interview about his favorite color. The old pals all say basically the same thing: Cassidy was a decent chap, with a melancholy side. There are also some tape recordings from journalist and gadfly Elliot Mintz, where a rather pompous sounding Cassidy declares that he wants to outgrow his teen idol stigma and play his own music, a laughable concept since, as a former Rolling Stone reporter tells us, Cassidy's dressing room was fully stocked with stuffed animals. The old concert footage is revealing: Cassidy looks small, impish, a harmless teenage boy doing a rock star impression, his hair in a nifty shag cut; he's dressed in costumes ranging from  white fringe jump suits to comfy overalls, as if he couldn't decide if he was Elvis, Mick, Ziggy Stardust or a Bay City Roller. The end came when a little girl was crushed to death at one of Cassidy's concerts. Disgusted and frightened by his fame, Cassidy promptly retired from touring.

David Cassidy, The Last Session, is incredibly moving, as much a requiem for 1970s pop music as  for Cassidy. There are many touching moments, like hearing Cassidy on voicemail, telling the producer of the documentary that he's not suffering from dementia at all, but that his body is simply failing after decades of alcohol poisoning. There's a beautiful clip of him playing an electric guitar, jamming on an old B.B. King tune, smiling, a kid again. The one moment that eclipses everything is when he listens to a recording of his father singing the old Broadway hit, "Wish You Were Here." Cassidy's  emotions erupt as his father's voice fills the studio. He tries to salvage the moment by saying, "I miss you dad," but it wasn't necessary. The anguish on Cassidy's face was as raw and gut-wrenching as anything ever seen in this era of cheap reality television. There's so much going on in the scene: Cassidy's awe of his dad's talent, his heartbreak that he and Jack  never truly connected, the pain of things left unsaid. Later, after Cassidy has died, his musician friends take an unfinished recording of David singing the same song, and patch together a new version. His voice was shot, but his phrasing is still perfect. Through modern technology, it all works pretty well. At last, David and his father have something in common - there's nothing left of either man but a few recordings.