‘Every interval,’ Gubaidulina explains, ‘creates a summation tone and a difference tone: an interval in the lowest register creates a difference tone which we recognise not as a tone but a pulsation.’ At higher registers we ‘hear the pulsation of the difference tone simultaneously with the original interval’.

Gubaidulina sees this transition from pulse to tone and back (and, eventually, the loss of even the pulse) as a metaphor for hope and despair. The Deceitful Face concerto exploits and explores this acoustical phenomenon and the emotional process of struggling against despair. As the piece unfolds, quiet passages inhabited by the flute soloist and other individual instruments are brutally invaded by outbursts from larger groupings. The flute part, impressively realised by Sharon Bezaly, finally gives way to the terrifying pulsing of the bass drum from which the piece first welled up.

Seven Last Words (1982) is a kind of companion piece to In Croce (1979), in which cello and bajan (Russian accordion) moved towards an explosive meeting from their extreme registers. Again, the crossing of lines is among the structural devices used to symbolise crucifixion. As is her custom, Gubaidulina asks her soloists to venture beyond the standard techniques of their instruments but, as ever, she does so in the service of expressiveness, not novelty. Her thorough command of instrumental colour (and, indeed, temperature) is put to brilliant use in evoking the contradictory emotions associated with Good Friday, from the pain and despair of the participants to the implicit hope of believers.