THERE is, perhaps, one album a decade that defies structure and logic.

Such is the case with the unlikely vocal marriage of Robert Plant - the only member of Led Zeppelin to remain aesthetically active - and Germanic bluegrass chanteuse, Alison Krauss.

By beautiful accident, their voices melt together to produce a sublime dream, where octaves mingle and the heart begins to kick.

It's more than mere musicality, however. Behind each artist lies a trail of heady influence and these roots also seem to entwine and produce an album made by like-minds and well as complementary voices.

Not since Tim Buckley has a record managed such sombre and uplifting reflection, lifting the listener to a different level. The blues is apparent throughout as indicated by Sister Rosetta Goes Before US and Trampled Rose and it's a spiritual aspect, rather than the more obvious sexual attack that remains the dominant flavour.

There are moments also - Please Read the Letter and Through the Morning, Through the Night that seem to tug the heart to tearing point. The Led Zep reunion may grab the headlines but I would suggest even they will never achieve such a luminous beauty.