"I write the music which I hear playing inside me,” wrote Rachmaninov. “I am a Russian composer, therefore my temperament, outlook and music are quintessentially Russian.” There are few more ‘Russian’ works than the Vespers or, more accurately, Rachmaninov’s setting of the All-Night Vigil, yet its first performance took place not in a Russian Orthodox church, but in a Moscow concert hall in 1915. A century on, performing the Vespers in the acoustically wonderful Milton Court, Jeffrey Skidmore took the imaginative decision to interleave its movements with solo piano works, played by Steven Osborne. It proved inspirational programming.

Performed by the soft glow of candlelight, with a little artificial help during the choral numbers, Ex Cathedra gave a beautiful rendition of the Vespers. With rounded vowels and softened consonants, you would never mistake them for a Russian choir, yet they make an impressively large choral sound for just 36 singers, the volume blooming nicely in Milton Court’s warm acoustic, without any congestion.

Choral balance favoured sopranos and altos, the basses – although 11 in number – being very soft-grained, occasionally lacking presence. They struggled down to the sepulchral B flat at the end of the Kiev chant “Lord, now lettest Thou”, but flexed vocal muscle in “My soul doth magnify the Lord”. There was peppery strength in the tenor line, especially during the Znamennïy Chant “Blessed art thou, O Lord”. Jeremy Budd’s plangent tenor shone in his few brief solos.

Skidmore’s direction was often cautious – almost too reverential, if that’s possible in a religious work. The slow pulse meant long pauses for breath, punctuating the musical line like a full stop when just a comma is required. At times I longed for something more urgent, more earthy… more Russian. Yet, with such luminous tone, it was hard not to succumb to the warm bath of choral sound, allied to the insertion of the piano interludes.

The piano works performed were selected from the Preludes and Études-tableaux composed shortly before the Vespers. The exception came with the C minor Étude-tableau from the Op.39 set, composed a year later. Its sombre mood, full of foreboding, contained an almost demonic force in the bass, plus a Boris Godunov-like peal of bells, not inappropriate when juxtaposed with the choral movements.

These piano interludes acted like meditations on the choral movements. The C major Étude, Op.33 no. 2, was a rippling reflection on the opening prayer, while the D major Prelude Op.23 no. 4 was poetically phrased. Osborne often found drama in these pieces – a drama that Skidmore sometimes found elusive – but also demonstrated tender, lyrical playing.

It was the combination of choral and instrumental that intrigued, each throwing fresh light on the other. Osborne often closed his eyes in contemplation during the choral numbers, while the sopranos, in turn, were transfixed by his wizardy at the keyboard. Not everything worked: candlelight slightly impeded my reading of the texts and, when an interval was taken, it seemed very odd applauding a religious work midway through (rather breaking the mood). However, as a fresh way of looking – and listening – to the Vespers, this performance was often revelatory.