Split into two sides of a producer-derived and an organic instrumentation per disc, Christina Aguilera’s third album oozes with sounds. After upping the ante of her bubblegum pop self-titled debut on Stripped, which moved her above and beyond the Britneys of the world, in many ways Back to Basics is a concept release.

It sets out the template from the get-go, being blatant that it’s going to take as its reference point the likes of soul singers and jazz makers that inspired a generation. It’s funny given that it’s still very much a ‘pop’ record in the first side, with Christina teaming with red-hot producer DJ Premier to lay down a series of cuts of big, better, best high-tempo vocal acrobatics. It sounds fantastic – Aguilera’s voice is an extraordinary gift, as she careens up and down octaves.

The second disc, produced and co-written by “Beautiful” songwriter and producer to the stars Lynda Perry (formerly of 4 Non Blondes) actually takes the reference points – the soul and jazz – and uses them powerfully well. While “Candyman” apes “Boogie Woogie Boy of Company B”, the likes of torch song “Nasty Naughty Boy” drips with sass and sex, and makes “Dirrty” look like a fully-clothed stroll in the park by comparison.

“Save Me From Myself” is a likely strong single, but nothing on Back to Basics quite matches the likes of Stripped’s “Beautiful” nor “Walk Away”, even if the second disc in particular is remarkably strong. Perhaps “Hurt” will be the number that defines Christina from this point on – it’s a big, soppy ballad, but it works in part because of her amazing pipes and the delicate restraint – there’s strings on it, and piano, but it never overawes the song. Christina is yet to make a defining album; Back to Basics is a laudable effort, more consistent than Stripped certainly, but there’s a sense that Christina is still only beginning.