Sinead O'Connor is known as much for her music as for her tabloid-goading tants.

Refusing to perform in New Jersey if the American anthem was played was one example; ripping up a picture of Pope John Paul II on television was another.

For such a livewire, however, her latest album, Theology, is a damp squib. Largely.

Among the eight original songs on her two-disc offering - the acoustic Dublin Sessions and the studio-treated London Sessions - there are exquisite tracks inspired by Old Testament psalms.

Something Beautiful, the first offering on both discs, is thus no empty promise, and one should give thanks for Out of the Depths and 33. But wedged between these personal responses to the state of the world, post September 11 (O'Connor's explanation of the work), are compositions that give more weight to the message than to the music.

If You Had a Vineyard, a puzzling rumination on the house of Israel and the men of Judah, is six and a half minutes of words strung together tunelessly.

And The Glory of Jah is a ploddingly mawkish hymn.

Then there are O'Connor's covers, of I Don't Know How to Love Him (Andrew Lloyd Webber and Tim Rice), Darker Than Blue (Curtis Mayfield) and By the Rivers of Babylon, which add nothing to the originals except afford us brooding versions in her pure, full-bodied voice.

Now that she's turned 40, O'Connor, still shaven headed, imp-like and a depressive, seems to have lost much of the fire that made her hot property during her heyday. It's as though Prozac has taken the edge off her manic brilliance.