But at Largo Thursday night, some 280 fans got a partial glimpse as a pop-up show by father-and-son partners Neil and Liam Finn found Campbell as a surprise guest on two songs, one of them a deeper-than-deep Mac track.

"Playing at Largo is really about having wonderful surprises occur," said the elder Finn, "and I'd like to welcome to the stage now a wonderful guitar player I've just had the extreme pleasure of learning how to play with -- and there's still more to learn, but for now let's welcome Mike Campbell!"

They then proceeded to perform a short but sweet version of Fleetwood Mac's 1969 single "Man of the World," a Peter Green song obscure enough that there was no applause of recognition when it kicked off, with most in the audience probably assuming it was yet another unreleased tune off the Finns' upcoming album.

Stevie Nicks said in a recent interview with Rolling Stone that the new version of the group would use the tour to spotlight at least a little material from the era before she and now-departed Lindsey Buckingham joined the band.

So Finn and Campbell dusting off a really, really pre-Buckingham-Nicks chestnut suggests they're taking that idea seriously... or maybe the two guitarists just thought it would be a fun first- practice exercise of their own accord.

There was no danger of the other song Campbell sat in on going unrecognised: a six-minute rendition of Davie Bowie's "Moonage Daydream," which had Campbell doing the initial coda soloing, but which eventually built into a twin-lead jam with Finn that really gave an idea of the fireworks that could happen in arenas later this year.

Australian Associated Press