It seems beyond John Butt’s Dunedin Consort to issue a recording that is less than perfect, and this ravishing account of Bach’s Christmas Oratorio is no exception. Not only does the clarity and beauty of the singing and instrumental playing blow anything else out of the water; Butt’s approach to realising Bach’s intentions under very specific performing conditions is committed yet flexible and open-minded.

For example, he uses two SATB choirs comprising just one voice per part – the maximum number Bach may have had at his disposal at any one time. Of the six cantatas comprising the oratorio, I, III and VI are sung by one choir, II, IV and V by the other. For those cantatas with trumpet parts (I, III and VI) he uses the “redundant” choir as “ripienists” to reinforce the part in the choruses and chorales – in reality, Bach would have used “apprentice” singers here.

As Butt writes in his excellent booklet note, “The aim then is to try and present the range of choral scoring that Bach seems to have used, from doubled vocal lines through to single lines for parts...