Though often associated with late '70s new wave music, the Police have always been in a class all their own.

And those very same things that separated the British reggae-rocking power trio from other groups 25 years ago remain true during the band's current reformation.

First and foremost: no keyboards. That might not seem like much of a differentiating factor, but actually, it's huge. Electronica epitomized pop music in the Police's heyday, and a similar slick wizardry pollutes rock'n'roll today.

But at Fenway for their second sold-out gig last night, there was no questioning their authenticity: The Police sounded fantastic.

Beginning with 'Message in a Bottle', Sting consistently took vocal liberties - modulating, bending, clipping and extending his notes to great effect.

Which brings us to the second important distinction: the Police's gift for improvisation and uncanny musicianship.

'Don't Stand So Close to Me' and 'Voices Inside My Head' were both delightfully lo-fi, with Andy Summers' looped guitar phrase coiling around Sting's undulating bass line on the latter.

Slamming suddenly into a hyper-jazzy reworking of 'When the World Is Running Down', Summers went on a bucking, wild ride of a solo.

Newly extended, 'The Bed's Too Big Without You' transformed drummer Stewart Copeland into a polyrhythmic slice-and-dice machine, and the trio reached a heightened state of musical chemistry during 'Driven to Tears'.

As musicians hell-bent on achieving perfection, it was inevitable that a stray piece of technology would float by: a secondary vocal materialized out of thin air for Sting to harmonize with during both 'Invisible Sun' and the encore, 'King of Pain', while stray animal noises spruced up 'Walking in Your Footsteps'.

But even so, the band's musical integrity and earnest intentions could teach current pop jokers a valuable thing or two.

© Boston Herald by Christopher John Treacy