'Volta', Bjork's sixth album, boasts a horde of big-name collaborators, from maestro R&B producer Timbaland to Antony Hegarty, frontman of Antony and the Johnsons. With these pop credentials, it may have seemed like Bjork was taking a step towards the mainstream. This is definitely not the case. She remains characteristically outlandish and experimental and despite the host of guests on the album, the essence is still very much Bjork with her soaring voice taking centre stage at all times.

'Earth Intruders', the opening track, starts the album off on a high note. It is undeniably a Timbaland creation, but melded well with Bjork's inimitable musical style. Catchy but eccentric, it layers tribal percussions over high-pitched chanting. It manages to avoid being too radio friendly with an outro that features foghorns blowing different notes that form a melody and the ambient noises of seagulls.

Antony Hegarty appears on the album for two duets, 'The Dull Flame of Desire' and 'My Juvenile'. On the first song the partnership is most successful. His voice can be excessively theatrical, but here the interplay between his deep, resonating voice and Bjork's swirling vocals creates a majestic and romantic sound. The 10-piece Icelandic brass choir are used to their fullest extent here, the horns creating maximum emotional impact.

The second of the Timbaland trilogy, 'Innocence', is most characteristic of his trademark hip-hop infused style. It features an aggressive beat, fun electronica noises and upbeat vocals. It is irresistibly ecstatic, with a persistence and urgency matched by Bjork's forceful vocal performance. Although Timbaland's fun, poppy style is very much apparent, it never smothers her distinctive sound. 

Mark Bell of techno group LFO provides the production on 'I See Who You Are', where a gentler side to Bjork is explored. Delicate plucked pipa (a Chinese string instrument) mournful horns and sweet lyrics celebrate a lover's body. 'Hope' is similarly guitar based, but with a Spanish tinge and the characteristic booming bass typical of Timbaland. 

The defiant 'Declare Independence' is jarring and discordant, with Bjork screaming "Declare Independence, don't let them do that to you" over a thumping drum beat and alien sounding synth guitar. It is the album's least successful foray into innovation and just makes for uncomfortable listening.

The album is a messy jumble of sounds and messages, with some gems in the midst. It may not always work, but it always keeps you guessing, which is what Bjork does best.

Sarah McIntyre

To buy 'Volta' from the RTÉ eshop click here.