Rachmaninov Vespers, Retrospect Ensemble, Cadogan Hall

What a superb selection of pieces this is. The music, for the three services during the night and dawn of Easter Sunday, is by its very nature fragmented – and despite the austere chant-based harmonies there is an astonishing variety of texture and timbre – but at the same time it creates a vast, overarching sense of the whole. The necessary details never stand in the way of the overriding sense of awesomeness.

Except that last night, at least to begin with, those details did get in the way. The balance wasn’t always even, which is pretty much vital for a chordal work such as this, and there were decidedly slippery moments of ensemble. It’s also tricky deciding how many singers you need: at the start, it sounded like there were too few - the voices didn’t always blend and the Cadogan’s acoustics didn’t offer much in the way of support. It was a bit like cranking up the car on a wintry Moscow morning.

Once things began ticking over, however, there was much to enjoy, and more crucially the atmosphere began to settle. Ruth Massey led the way with a fabulously well-oiled alto solo that was worth the trip out on its own, and the sopranos and altos began to provide that hovering luminescence that Rachmaninov’s harmonies cry out for. The basses took a little longer to get going – the basso profundo descending scale at the end of “Nyne otpushchayeschi” was somewhat lavatorial – but by the second half they were in their element: rich and strong, the hard edge gone, and plenty of time for us to admire some heftily impressive low notes.

This early clanking of gears was a shame, as it’s the music for the first service that really creates that intense atmosphere. However, the first piece from the second service did everything it was supposed to. Surely there can be few a cappella works that are so orchestral as the Vespers; in this movement we got the first hints of morning blossoming though lower-string and French-horn tenors and altos, stirring us awake before the brass-like bass entry: it would make a fine prelude to the second act of any opera. The blend was much better here – glistening upper voices shone above solid, stentorian bass lines – and it continued to improve. The final rousing “Kontakion” was a truly impressive outburst of joy. It was a pity not to walk out into an Easter morning sunrise.

Between the music for each service we got short bursts of Rautavaara, Górecki and Kalinnikov: the Górecki was particularly beautifully sung. Truth be told they weren’t really necessary, but they complemented the Vespers well.

Rachmaninov’s choral masterpiece is something of an old wine that needs to be kept by a choir for a decade or two before it really gives up its innermost secrets. This performance felt like the bottle had been opened a few years too early – but there was still plenty in it to feel like a treat.

Retrospect Ensemble will be performing Bach cantatas for countertenor with Robin Blaze at the Wigmore Hall on 10 February. The next concert in the Cadogan Hall's Lux Aeterna series is by Trinity College, Cambridge on 18 March.