Hot on the heels of not one but two Proms just last night, the Latvian Radio Choir turned its attention from Rachmaninov to Shostakovich for the lunchtime concert at Cadogan Hall. Shostakovich and a cappella choral music might not immediately spring to mind, and his Ten Poems on Texts by Revolutionary Poets rarely gets an outing. Today we were offered five of the ten, interspersed with six from Shostakovich’s set of 24 Preludes and Fugues, performed by Russian pianist Alexander Melnikov.

Much has been written about Shostakovich’s relationship with the Soviet State, and its influence on his music. When was he writing to please the politicians, when was he writing his ‘own’ music, what hidden codes did he use to subvert or hide messages in his music? There is clearly no straightforward answer to this. However, it is fair to say that the two works on offer today sit far apart on the spectrum of pleasing the authorities versus the ‘true’ Shostakovich, whatever that is. With both works hailing from the same year (1951), with consecutive opus numbers, they made intriguing companions in today’s programme.

The Ten Poems were clearly written to please the Union of Composers, and the Central Committee of the Soviet State, drawing on texts about the first failed 1905 Russian Revolution. They range from a sad lament for executed soldiers, through angry defiance at the Tsar and his actions, to praise for a righteous victory in defeat. The most immediately impressive aspect of the Latvian Radio Choir’s singing (and Sigvards Kļava’s direction) is the dynamic range they achieve. Many choirs can sing loud (although with just 24 singers, the maximum volume here was almost off the scale), but not many can maintain a warmth and depth of tone when doing so. Fewer choirs still can also sing very quietly, with intensity and again, retaining a beautiful sound at the same time. This was most striking in the tenor voices, ranging from an incredibly light, heady yet beautiful tone when singing quietly, right through to a powerfully fervent full-bodied fortissimo. Never did the singers sound forced when singing loudly, nor weak when quiet.

So in the first of their selection, To the Executed, the basses enter alone, very quietly, soon joined by the tenors. The blend was perfect, with a rich, smooth sound, and the tenor line floated over the top at the close was sublime. The combined male voices declaiming passionately at the start of The 9th of January, the lusty, smooth altos at the beginning of The last salvos have sounded and the mammoth sound from the full voices in the bitterly celebratory They’ve won… – these are voices to be reckoned with. But the highlight was definitely the sad lament of The last salvos have sounded, a lullaby to the dead, with its impassioned “Spite” (sleep), finally echoed by those wonderful light, heady tenors. These propaganda pieces shouldn’t really work, but in Kļava and his expert choir’s hands, they were powerfully affecting.

The Preludes and Fugues tend more towards Shostakovich’s compositions “for the desk drawer”, Shostakovich fully expecting they would at best find disapproval, at worst be banned. Sure enough, their frequent use of dissonance, at the same time as their use of fugue (perceived as too Western and backward-looking) led to significant criticism. Shostakovich includes references to Bach, but also ideas from his own work, and they stand out as one of the highlights of his solo piano repertoire. Melnikov selected the first four, and numbers 7 and 8. With the piano placed left of centre, the choir on the right, Melnikov had a low-key stage presence, and his playing was at all times thoughtful and calm, even in the technically demanding relentless Fugue of no. 3, for example.

The first Prelude was incredibly tender, even wistful, and the following Fugue, which never strays from C major, had a tremendous sense of calmness, with Melnikov bringing out the bell-like lines in the louder section with subtle surety. Melnikov brought out the darkness of the supposedly G major third Prelude, contrasted with its sprightly Fugue, and the folk-like theme of the fourth Fugue was smoothly lyrical. But it was in the comically grotesque eighth Prelude, so typically Shostakovich, followed by the lengthy angular and mysteriously wandering Fugue that his precise articulation was so captivating, even in its final descent to the depths of the keyboard. Ever gracious in sharing the stage and the final applause with the choir, this was a wonderfully understated performance.

Placing selections from these two such different works side by side serves to highlight the challenge of detecting Shostakovich’s true voice, if such a thing exists. But in performances as powerful and committed as these, perhaps this no longer matters.