''Crazy in Love'' is the best song on ''Dangerously in Love'' (the album is, oddly enough, named after an old Destiny's Child song); it's a simple, irresistible combination of triumphant horns and a wicked hip-hop beat. But the song also hints at what's wrong with the album: its vision of romance is profoundly unconvincing.

If Jay-Z and Beyoncé really are a couple, that might explain why their collaborations sound so tepid. When he teamed up with Mya for ''Best of Me Pt. II,'' Jay-Z spat out one clever, rude pick-up line after another (''That's high-school, making me chase you 'round for months/ Have an affair, act like an adult for once''), and on Missy Elliott's ''One Minute Man (Remix),'' he quoted ''Independent Women Part I'' while explaining the rules of a one-night stand. When he records with Beyoncé, though, Jay-Z's mischievous wit disappears; on ''Crazy in Love,'' he barely even makes reference to her.

For her part, Beyoncé explains how ''Your love's got me looking so crazy right now,'' but her vocals -- as deft and accurate as ever -- convey none of the giddy rush that the lyrics describe. Near the end, when she trills, ''You're making a fool of me,'' she sounds decidedly unfoolish, as Ashanti once put it.

The first half of ''Dangerously in Love'' has some impressive moments -- Beyoncé arpeggiates her way up and down the scale whereas most of her contemporaries merely slide, and it's fun to hear her mimic the pizzicato line in ''Naughty Girl.'' But it's not much fun to hear her try to sing like a ''naughty girl,'' and by the time the album's ballad-heavy second half arrives, you may start hoping that the other two Destiny's Children will show up to set things right.

They don't, and it's not just their harmonies that are missed; it's the girl-group exuberance. Together, the three might have found an amusing way to flirt with Jay-Z, or Sean Paul, or Big Boi, from OutKast. Without them, Beyoncé hedges her bets, retreating to the safety of torch songs, like the creepy bonus track ''Daddy,'' where she croons, ''I want my unborn son to be like my daddy/ I want my husband to be like my daddy.''

Maybe this album is merely a misstep, and maybe Beyoncé has yet to record the brilliant solo album that people expected. Or maybe it's proof that she isn't quite as versatile as she seemed. She's a strong and independent singer, no doubt, but maybe she seems strongest and most independent when she's got a posse behind her.