CLASSIC ROCKERS GIVE L.A. FANS '70S, '80S HIGHS.

Byline: Gerry Gittelson Staff Writer

It was as if Los Angeles rock fans traveled back in time last weekend, as veteran outfits Aerosmith and Cheap Trick teamed to sell out the Forum on Sunday, preceded Saturday by Bryan Adams' well-received performance at the Universal Amphitheatre.

All three have remained popular over the last two decades even as most of their contemporaries have either vanished or been relegated to the club circuit.

Boston five-piece Aerosmith proved remarkably energetic throughout its two-hour concert, and the diverse crowd overwhelmingly approved such classics as ``Love in an Elevator,'' ``Jaded,'' ``Cryin','' ``Walk This Way'' and, of course, staples ``Dream On'' and ``Sweet Emotion.''

Singer Steven Tyler hasn't lost his Jagger-esque strut, and he was in fine vocal form. And it's hard to imagine him ever working up such a sweat, even in the early days (or daze) of Aerosmith's career, as he zig-zagged his way across the huge stage and adjoining ramps.

Cheap Trick was nearly as well-received, tearing through a 10-song set of its most popular material. The Rockford, Ill., foursome, led by singer Robin Zander and wacky guitarist Rick Nielson, reached an early peak with ``I Want You to Want Me,'' followed by ``Dream Police,'' ``Top of the World'' and ``Tonight It's You.'' By the time the group closed its 10-song set with ``California Man'' and the signature hit ``Surrender,'' 40 minutes had breezed by in no time.

Canadian-bred Adams, who always has had more teeth in his music than in his smile, has stripped things down to a three-piece. But he's been a consistent hit-maker since bursting on the scene in the early '80s, and he had plenty of worthy material Saturday. ``Summer of '69'' got the crowd on its feet, and Adams maintained the momentum throughout the set.