Beyoncé - I Am... Sasha Fierce

It's very rare that a double album works or is indeed necessary.

Christina Aguilera tried it with Back To Basics and, while it wasn't short of decent tunes, ultimately it would have benefited from being a single disc by losing some of its weaker, more self-indulgent moments.

Beyonce's at least has a concept behind it - the first disc, I Am is intended to show her more personal side and consists predominantly of ballads, while disc two, Sasha Fierce is intended to demonstrate her on stage alter-ego and is bursting at the seams with the kind of booty-shakers she's made her name with.

Available in either eleven or sixteen track versions, it's not short of stand-out moments: from the Ryan 'Bleeding Love' Tedder-produced, Halo which blends her gorgeous vocal with a pounding drum beat and synths to an original new take on the hymn, Ave Maria.

On the Sasha Fierce disc, edgy electro track, Radio is well worth checking out as is Sweet Dreams, a demo version of which has been circulating on the internet for some time under the name Beautiful Nitemare - we dare you to find a dirtier bassline. However, Diva with its irritating computerised vocals and pointless lyrics about being 'the female version of a hustler' is a complete waste of space.

All in all, I Am... Sasha Fierce does what it sets out to do, demonstrating both of the sides of Beyonce that we know and love - her ability to belt out a beautiful ballad and to get us on the dancefloor. As to whether it warranted a double disc release... well, the jury's out on that one.

• Take a look back at Beyoncé's career to date in pictures
• Watch the video for her new single, If I Were A Boy