Monteverdi's last publication has always been something of a stepchild in his output, perhaps partly because of its sheer size and variety: there is lots of music in it that is hard to pigeon-hole.

Various pieces here are well known and often heard, but among the almost four hours of these discs there is plenty more that has attracted very little attention. It is a massive assembly of some 40 pieces, some apparently very early, many of them from those mysterious years after the 1610 Vespers, and a few perhaps very late. In style they range from the purest academic polyphony of the stile antico to the most elaborate concerted music with intricate and showy instrumental parts, from the simplest melodic writing to virtuoso floridity with extreme vocal ranges.

In this complete recording, which has long been needed, Konrad Junghanel has rightly concluded that it would make no sense to record the collection in its original order. So he has effectively made the flrst and third CDs into approximate vespers collection with the second CD containing most of the music that cannot be fitted into the others. (New listeners may want to beg in there.) This works extremely well, not least because those who are not ready to sit through it all at one sitting can get a satisfying musical unit from any one of the discs. The 12 singers of Cantus Cölln have among them enough variety of colour to keep the sound lively and interesting. They are always clear, disciplined and balanced; and Junghanel directs the often episodic works with a flrm control of their shape. The peerless Johanna Koslowsky leads much of the time in the larger pieces and contributes marvellous solo numbers. In some of the smaller ensembles Elisabeth Popien makes a superb top voice, sounding occasionally almost like a male alto. For the large-range bass solos Stephan MacLeod makes the impossible lines sound almost effortless.

If they just occasionally seem a touch staid in comparison with the Italian singers who have been so successful in recent recordings of Monteverdi and his contemporaries, that may just be the price of recording such an enormous collection . But they do have the benefit of a thorough seriousness of purpose which may well have its place in a monumental recording project such as this.

It must be said that the instrumentalists of Concerto Palatino never for a moment sound tired: from the miraculous cornetto duets of Bruce Dickey and Doron Sherwin, to the beautifully blended sackbuts, the always vivacious violins and the perfectly balanced continuo group, they repeatedly add energy to the performances.