Anniversary releases carry a certain pressure – a need to define, represent, embody. Do you gather up your greatest hits or strike out into new territory, return to what you do best or startle and surprise? Celebrating their 15th anniversary this year, the British vocal ensemble Voces8 have refused to make the choice. The double disc ‘After Silence’ gives them space to do it all and it’s the breadth – not just of repertoire but of sound, technique and approach – that makes it so arrestingly excellent.

With Decca the eight-voice a cappella ensemble moved increasingly into atmospheric, often over-produced albums aimed squarely at the easy-listening market. With ‘After Silence’, released on their own label, the group return to their classical roots, and remind us of their chameleon ability to tackle everything from Bach, Mahler and Monteverdi to Britten and Ešenvalds on its own terms and to rival the specialists while they’re at it.

Take Monteverdi’s Lagrime d’amante – the exquisitely dolorous sestina the composer wrote to mark the death of soprano Caterina Martinelli. Vivid and boldly shaded through all the voices, operatic in expression but pinpoint-precise in acoustic, it couldn’t be further either from the warm bath of choral blend we open with in anthems by William Harris and Parry (recorded in Trinity College Chapel) or the gut-string rasp and snap of Bach’s early cantata Nach dir, Herr, verlanget mich (No 150), in which the group join forces with the Academy of Ancient Music.

The musicianship here is dazzling, and nowhere more so than in Britten’s Hymn to St Cecilia – mercurial and responsive in its conductorless precision, taking risks with tempo and volume but always pulling them off. It’s exhilarating to see the Britten and Bach programmed alongside popular choral classics such as Stephen Paulus’s The Road Home and Whitacre’s Sleep, and if the album’s four ‘chapter’ divisions (‘Remembrance’, ‘Devotion’, ‘Redemption’, ‘Elemental’) seem a little interchangeable in theme, the listening experience flows smoothly, offering just enough fizz and friction in a programme dominated by the slow and radiant.

Everything has been captured lovingly but truthfully, allowing us to hear the individual voices behind the group’s signature blend. The result is the best thing Voces8 have done in ages. I can’t wait to hear what comes next.