The first post-greatest hits record is a tricky proposition for any act, but particularly so for a manufactured pop group, whose shelf life seldom exceeds a few albums.

Girls Aloud are no exception; indeed, they have more to live up to than most.

2006's hits package The Sound of Girls Aloud was a surprise Christmas bestseller, their first number one album in the U.K., and it included the infectious "Something Kinda Ooh!" It gave them one of the defining hits of their career.

However, their last studio album, Chemistry, stalled in the charts, and now Tangled Up is the group's first to contain no well-known cover versions, the chart fortunes of their previous records having being reversed to varying degrees of success by the release of timely renditions of the Pointer Sisters' "Jump," the Pretenders' "I'll Stand by You," and Dee C.

Lee's "See the Day."

Taster single "Sexy! No No No..." is one of the most daring songs they've yet released.

A pounding electro-punk number with an extended, vocodered intro and a chorus which, while catchy, could hardly be described as danceable, it eased into the U.K.

Top Five, but had a relatively short stay on the charts and didn't seem to bode well.

However, as seems to be something of a pattern with Girls Aloud albums, second single and album opener "Call the Shots" is the real revelation.

By far the most subtle single of the girls' careers, it's an elegant electro-pop ballad delivered with a restraint and maturity to rival groups of twice their age.

Writing team Xenomania may have been working behind the pop scenes since long before Girls Aloud were formed, but they remain adept at crafting lyrics to suit the group, all of whom are still just in their early twenties.

The line "I won't cry because I've stumbled through this far" says more about the confusion, naiveté and bruised wisdom of youth at the precipice of maturity than a thousand Britney Spears ballads.

Elsewhere, Tangled Up is a short, sharp and tight collection of some of the most exciting music in a particularly exciting career.

Girls Aloud albums always come brimming with ideas, but while they could previously leave the overall collection as something of a mishmash, here they succeed as a perfectly constructed whole without becoming a tedious homogeny.

More than this, though, it's a considerable artistic step forward, with the sugar rush of songs such as "Love Machine" and "Something Kinda Ooh" toned down somewhat in favor of a more aloof, knowing sexiness.

Not that the Girls aren't having fun.

"Close to Love" stops around two-thirds in as they yell warnings such as "Guy with the terrible hair, back off!" and "Fling" boasts a manic shoutalong chorus assuring a prospective lover that "It's just a bit of ding-a-ling baby!" Elsewhere, "Black Jacks" sounds like a lost Ace of Base classic, "I Can't Speak French" achieves the kind of effortlessly sultry cool which the Sugababes have spent a career striving for, and "Girl Overboard" is like an aggressive, relentless cousin to their previous career highlight The Show.

However, the song that -- alongside "Call the Shots" -- may come to define this album (and indeed may be their greatest recorded achievement to date) is closer "Crocodile Tears." It's easy to overlook the vocal accomplishments of Girls Aloud; despite their talent-show beginnings, they can be difficult to distinguish as individual singers and are often seen by critics as little more than an attractive blank canvas for the wild pop experiments of their production team.

However, "Crocodile Tears" cuts through their tabloid notoriety and occasionally cartoonish images with astonishingly intelligent vocal performances.

The lyrics tread a familiar path of heartbreak, but lines such as "Why on earth did you leave me?" are delivered not with anger or pain, but in a resigned, almost bored sounding whisper.

And herein lies the genius of Tangled Up.

Girls Aloud have grown up, and they're not shedding their clothes to prove it.

They've been through the first flush of love and despair and come out the other side, as we all do.

A little more bruised, a little more wise, and a lot more interesting.