J.S. Bach’s ‘O Lamm Gottes, unschuldig’ (O innocent Lamb of God), BWV 656, is a substantial organ chorale partita placed at the heart of the mature Eighteen Chorale Preludes from the composer’s time in Leipzig. As befits a Good Friday chorale setting on the Agnus Dei, it emphasises its tri-partite form with extraordinary dramatic impact. From the quiet supplication of the opening pages (the ‘trumpet chorale’ intensifying its quest for mercy in the embellished repeat of the opening), the mood becomes restless as a swinging counter-melody encircles the cantus firmus, now portentously in the bass. Here, all hell is let loose as a triplet counter-subject drives inexorably in desperate defiance (ringing out on the trumpet in a repeated figure of top C sharps). An anguished chromatic passage simply collapses the music, surely at the point of crucifixion. Is that the final ‘coup’, like Bach’s devastating treatment in the second Kyrie of the great ‘Organ Mass’ (Clavierübung III)? No, here we have a reprieve – a plea in rapier-like quavers racing higher towards hope of salvation.
In performance, the players should carefully map out the architecture; deciding tempo relations, dynamics and rhythmic gestures are key in building inexorable momentum and celebrating the dramatic contrasts of this magnificent edifice.
- Trumpet in C
Also available as part of A Bach Notebook for Trumpet.