Never one to stick to a tried and tested formula for too long, it was surely only a matter of time before Björk Gudmundsdottir went a capella. In fairness, as one of the most talented and original artists of the last ten years she can probably hold her own in this area better than most. However, what made Björk great in the first place was usually a group of producers and musicians who could glue her unorthodox vocal stylings into a much more approachable and melodic proposition. Certainly, 'Vökuró', one of a few songs to be sung in her native tongue has a stark beauty to it but that's mainly because she's backed up by the Icelandic choir. When she does go it alone on 'Öll Birtan' - featuring multiple layers of her own vocal on top of one another - the results are self-indulgent and banal. Assistance from old hands like Mike Patton and Robert Wyatt also fail to raise the ante. Thankfully, there a few reminders of electronic pop successes and it's no coincidence that some of the best tunes ('Oceania', 'Triumph Of A Heart' and 'Who Is It') feature input from regular collaborators Mark Bell and Valgeir Sigurdsson. So sometimes sticking to what you know is the best option after all.