For much of David Bowie's show Wednesday night, a floor-to-ceiling scrim separated the singer from his audience at Merriweather Post Pavilion. When Bowie opened the show by strumming a 12-string acoustic guitar and singing his 1969 single "Space Oddity," a giant image of him (in a monochromatic turquoise) was projected on the scrim. The effect made for terrific high-tech theater (the live Bowie even stepped out of the way of the giant Bowie's stomping feet), but the scrim also symbolized the fatal flaw in Bowie's music: its calculated detachment and its emphasis on image over substance.

Bowie has announced that his current "Sound & Vision" tour is the last time he'll perform most of his old hits in concert, and he touched on nearly every chart success he's ever had. The projections on the scrim and the two opaque screens flanking the stage turned most songs into live music videos. For "Let's Dance," a blonde in a skimpy playsuit did the tango with the giant Bowie image on the scrim while the live Bowie swayed on the runway out front. During "Young Americans," giant orange flames licked at the scrim while the tiny live Bowie sang below.

Bowie was nattily dressed in a dark tailored suit; with his strawberry blond hair combed backward, he looked like an older Harry Connick Jr. Bowie was backed by a strong art-rock quartet led by guitarist Adrian Belew. Belew added his large arsenal of feedback, tremolo and screaming sustain noises to Bowie songs like "Fame" and "Station to Station" and to his own "Pretty Pink Rose," but he is essentially a sideman who can only complement the music. And the music was hampered at its core by Bowie's bloodless vocals.

Whether he was imitating Mick Jagger on "Rebel Rebel," Daryl Hall on "Fame" or Lou Reed on an encore version of Reed's "White Light, White Heat," Bowie always sounded like a wan, second-best copy. In the end, his greatest-hits show recalled the recent tours of another British singles star of the '70s: Elton John. John, though, has a better voice, better melodies and a better sense of humor. Bowie returns to Merriweather tonight.