After 25 years and 14 albums, it seems a little churlish to complain that Robert Cray has been mining the same low-key, mellow Memphis soul-blues groove for well over two-thirds of his career.

Not only is that kind of the point -- he's found his sound and he's sticking to it -- but many of Cray's influences didn't vary all that much on record, either.

Besides, if an artist were going to make a living out of carrying on a tradition, it only makes sense that all his records would be cut from the same cloth.

And so is the case with Robert Cray.

Not long after Strong Persuader became an unexpected crossover hit in 1986 -- which was hard to imagine then and seems like a near impossibility now -- Cray decided that he would rather pursue the sound of Stax and Hi soul than be a full-fledged bluesman.

He punctuated his songs with stinging licks not dissimilar to Albert King, but the sound was closer to O.V.

Wright.

But what really separated Cray from his forefathers is that instead of getting dirty and gritty, he stayed classy and tasteful.

At first, that seemed like it might have been a market concession, but as the years rolled on, it seemed like a conscious matter of taste, which is something Twenty, his 14th proper studio album, confirms.

As his second album on Sanctuary and his fourth since leaving major labels behind, Twenty is relaxed and well scrubbed, to the point of being kind of sleepy.

Superficially, that increased laid-back vibe is the biggest difference, but beneath that polished surface there are some unexpected barbs, whether it's how the lightly swinging "My Last Regret" camouflages some vicious intentions or how the title track is one of the harshest anti-Iraq War songs to date.

These are the songs that indicate Cray is more restless than his recordings make him seem, and if the production on Twenty weren't so slick, these emotions would jump to the forefront.

Alas, this album is as polished and as refined as any recent Cray record.

Which hardly means it's bad -- it's thoroughly pleasant, the rare up-tempo cuts pack a punch, Cray is an effective soul singer -- but it just sounds a bit too familiar.

And that's unfortunate, because a close listen reveals that Cray is taking some subtle risks.

They're just so subtle, they're hard to catch without very, very close listening.