In the last 10 years Daryl Hall and John Oates have had their share of ups and downs. Currently, the duo is enjoying an "up"--the biggest in their career. So it wasn't surprising to find them projecting a triumphal spirit from the stage during a sold-out performance at Merriweather Post Pavillion last night.

What was surprising was how they went about it. From the start, they fused the studio finesse of their recordings with a rhythmic intensity apparently reserved for concerts. Hall, blond and lanky, was in particularly good voice, giving a soulful slant to the bands' numerous tuneful melodies, including "Rich Girl," "Kiss On My List" and "I Can't Go For That."

Oates, dark and stocky, chimed in on the harmonies, sang an occasional number (including "Funky Broadway,") and joined guitarist G.E. Smith in letting sparks fly on several instrumental breaks. Consistently, the entire band blended elements of pop, rock, R&B, and funk without compromising any of them and, apart from a bit of clenched-fist posturing on Hall's part, did it with winning showmanship.

Scandal, a rock sextet from New York, opened the show. In a striped leotard, lead vocalist Patty Smyth could have passed for Pat Benatar's younger sister, although Benatar's vocal power and range proved beyond her reach. Even so, Smyth and her band recreated songs like "Love's Got a Line on You" with brassy assurance.