The Cowboy Junkies didn’t so much burst onto the roots-rock scene with The Trinity Session in 1987 so much as they crept onto it, masters of restraint in their moody evocations of Margo Timmins’ breathy ruminations set over brother Michael’s teasing mandolin. Less known for their originals, they completely redefined such seemingly disparate classics as Velvet Underground’s “Sweet Jane,” the Marcells’ “Blue Moon” and the country double-whammy, Hank Williams’ “I’m So Lonesome I Could Cry” and Patsy Cline’s “Walking After Midnight.” I’m sure their fans would insist the Junkies charted their own original path from that auspicious debut; others are still waiting.

All of that makes Trinity Revisited seem unnecessary and precious as they try to recapture a career that never quite happened. Returning to the scene of the crime, Toronto’s Trinity Church (captured on the bonus DVD), the bandmates recruited peers and fans Natalie Merchant, Vic Chesnutt and Ryan Adams to see if they could recapture the magic.

And they almost succeed.

By the fourth track, all the guests have announced their arrival. Merchant, whose measured vocals have too closely matched Margo’s over the years, takes control on the one original gem, “Misguided Angel,” rising to an aching wail that might have been 20 years in the making and almost worth the wait. Chesnutt, always a sly one, makes “Blue Moon” even slyer with his creeping insinuations. And Adams makes this band rock about as hard as it ever will on “I Don’t Get It,” with Michael Timmins’ electric guitar almost coming to life for a grinding solo. Still, it all comes down to “Sweet Jane,” their one big moment, which alternates between a raucous psychedelic jam and a mid-tempo groove for its eight minutes, another Junkie tease but with some rare guitar muscle.

Trinity Revisited is a frivolous, fun and decidedly nostalgic step back. Too bad the Junkies may never go too far forward. No hurry.