Sure enough, predictability was a problem for much of Sunday night's show at a packed Compaq Center, from the carved-in-stone set list to the between-song ruminations of Lindsey Buckingham.
Even with four solid new songs peppering its mix of '70s and '80s hits, this sounded more like The Dance revisited than Fleetwood Mac revitalized.
Indeed, in 2 hours and 20 minutes, the 17-song The Dance album was played in its entirety, along with four of the five additional songs on The Dance video. (Over My Head didn't make the cut.)
Those are great songs, and the band still rocked with authority. But what this concert sorely needed was fresh material, new to the reunion.
That's what it finally got more than halfway through the 26-song show, when Stevie Nicks returned after a costume change to sing her solo hit Stand Back.
Played more up-tempo and with rousing authority, it brought the show a vital taste of rediscovery.
Other surprises to follow were Christine McVie's haunting Oh Daddy; a lilting encore of Farmer's Daughter; a punchy yet powerful Second Hand News; and Buckingham's self-indulgent Not That Funny.
It sandwiched this show's most odious instance of '70s staleness, Mick Fleetwood's interminable drum and percussion solo.
But Fleetwood and bassist John McVie laid down stout rhythms, while Buckingham was a flamboyant workhorse.
One of rock's guitar virtuosos, he delivered dexterous solos for songs such as I'm So Afraid, and he commanded the stage alone on acoustic guitar for Big Love and his solo-disc number Go Insane.
That song, like several others, was marked by subtle reinventions, as it opened with a dramatic poetry recitation.
Nicks' new Sweet Girl displayed good three-part harmonies, while Buckingham matched her accusatory singing on Silver Springs, as first seen on the concert video, with a defiant, stare-down aggression of his own.
But this quintet of former lovers and spouses, backed by five session players, has largely shed its soap-opera past. Fleetwood Mac is now one big happy family -- especially with the dough rolling in again.
While that stance has blunted its edge, the band has been buoyed by an assured new professionalism and a heartening sense of rededication.
Visibly, Fleetwood Mac has held up. Nicks still swirls and dances, and they all look time-warped in their preservation from the '80s.
For this reunion to continue, they'll need more than four new songs to sustain it. Otherwise, Fleetwood Mac is an oldies act. But for now, in terms of sheer musicianship, it's enough just to have them back.