David Cassidy, chin in hand, with his “Partridge Family” co-stars in 1970. Clockwise from top left: Shirley Jones, Dave Madden, Cassidy, Susan Dey, Suzanne Crough, Danny Bonaduce and Brian Forster. (AP/AP)
Editor, staff writer

I was not a David Cassidy fan. He was the yucky grown-up boy in the afternoon rerun I watched religiously because it's what was on. Even then I hated the hair. And yet of all the Partridge faces, my eyes kept going to his. Now I understand why.

A lot of what we credit as good acting is just charisma. But here's how you know Cassidy could act: Watch him sing.

The songs on "The Partridge Family" were so lame (I'm sorry, it's true), but Cassidy owned them. He'd be fake-performing with his TV siblings — a whole passel of younger, cuter faces on the stage with him — but while they stood there basically inert with their unplugged instruments, big brother Keith Partridge was totally rocking out. In real life, Cassidy was a Hollywood 20-something with far cooler musical tastes, but he never seemed less than fully committed to this bubblegum pop, keeping fluidly in sync with the beat of the music and the emotions of the song.

And that made him the biggest star in the world — for about two years.

No, really — he was huge. He topped the charts, sold out Madison Square Garden, posed naked for Rolling Stone, and had girls running through the streets and screaming for him.

Now it feels like alternate history — did this really happen? David Cassidy? Even more surreal is to read the critics of 1971-1973, gamely trying to compare him to Elvis or Sinatra, other guys who'd inexplicably made girls scream. But how could they have known better? Rock was still new, relatively; teen idols hadn't yet grown old. Only five years had passed from the Beatles at Shea Stadium to the "Partridge Family" premiere. Everyone else was willing to wager this David Cassidy moment could endure.

In his early roles, Cassidy could project a masterful sulk — if he kept his dazzling smile in check. (Michael Ochs Archives/Getty Images)

Except that, ultimately, there just wasn't much there musically. A perfectly nice voice, and you can hear his early Broadway experience in the way he emotes through "I Think I Love You" — an enchantingly neurotic ballad (I woke up with this feeling I didn't know how to deal with, and so I just decided to myself, I'd hide it to myself) that helped a generation of young women make excuses for bad boyfriends yet to come. But the other songs were fairly generic, and he had no real band to lend him cred.

A critic for the New York Times caught his act in 1972 and pretty much had his number: "The significant element here is sensuality and theater, not music. . . . His understanding of the implicit dramatics that he can stimulate when he struts around the stage in his gleaming white jump suit reveals a markedly mature familiarity with the core qualities of show business."

Quickly he was on the path that other teen idols would follow — it's just that Cassidy had to travel it first. The awkward attempts to seem more edgy; the fizzled follow-ups; the retreats to Japanese and British fan bases after he'd fallen off American playlists; the painful, public battle with addiction. He tried to reboot his acting career and scored an Emmy nomination with a dramatic made-for-TV movie role. But a cop procedural built around him — "David Cassidy: Man Undercover" — didn't last a full season.

Some of the other teen idols internalized the lessons of Cassidy. Bobby Sherman saw the work drying up and got himself trained as a paramedic. Cassidy's half-brother Shaun stowed his Top 40 earnings into real estate and leapt for dear life into an enduring career as a producer before he hit his Tiger Beat expiration date.

David Cassidy performing in Las Vegas in 2000. “I couldn’t understand,” he said of his teen idol years, “how people didn’t see that I was a guy playing a part.” (Handout/Epa-Efe/Rex/Shutterstock/Handout/Epa-Efe/Rex/Shutterstock)

It had taken him a long time to come to terms with that role. "I couldn't understand," he told The Washington Post in 2002, "how people didn't see that I was a guy playing a part." But that was the gig. And once again, David Cassidy owned it.