At first, it seemed that Alicia Keys might have been swallowed up by her machine. At last night’s concert at a half-filled Value City Arena, she initially showed up gamely singing and dancing with six dancers dressed as mimes, a quartet of backup singers, a full band, and a light show worthy of Vegas. The production was slick, but Keys’ personality was swamped by the show.

Then she sat down at the piano, and the world righted itself.

At first, it seemed that Alicia Keys might have been swallowed up by her machine. At last night’s concert at a half-filled Value City Arena, she initially showed up gamely singing and dancing with six dancers dressed as mimes, a quartet of backup singers, a full band, and a light show worthy of Vegas. The production was slick, but Keys’ personality was swamped by the show.

Then she sat down at the piano, and the world righted itself.

In and of itself, the staging of the show, which featured a curved video screen, a long white runway and a close relative of the spaceship from Close Encounters of the Third Kind, from which the musicians and Keys’ piano appeared and disappeared amid clouds of smoke, functioned with precision. It’s just that this structure could have accommodated almost any singer with equally bland results. During dance-accompanied numbers, which made up about half the concert, the choreography was generic and predictable and Keys, not a naturally talented dancer, seemed to be working so hard to get through the moves that she couldn’t do more than an acceptable minimum vocally.

Not so when she was at the piano, whether alone on stage or accompanied by full band and backup singers. There she seemed completely at ease, and her soulful voice could soar.

While some of the danced numbers were fragments, most of the piano ones were full songs. Keys reached back to her first album for the touching Butterflyz and the R&B anthem A Woman’s Worth.

She also brought raw energy to the songs from her latest album, As I Am. On the CD, these are smooth and polished, but they benefited in live performance from a little roughing up and the addition of a bittersweet edge: Superwoman, for example, can sound dully feminist, but with Keys’ confession that it was written at a point when she didn’t feel super at all, it takes on a bittersweet poignancy. Like You’ll Never See Me Again had a rich, bluesy tone.

Keys also made an understated appeal to concertgoers to donate to help children affected by HIV in Africa, showing pictures of some of the kids she saw during a recent visit there.

As the concert went on, the initial frantic pace slowed down enough to allow a more natural singer to emerge.

With the originally scheduled Jordin Sparks sidelined by illness, the concert opened with Keys’ longtime backup singer Jermaine Paul sliding through a set of soft rock songs, accompanying himself on acoustic guitar. Akon followed, with a set of vigorous, Caribbean-accented rap, warming up the crowd with Top 40 hits and with the progressive removal of various articles of clothing, until he was finally performing bare-chested.