EVERY time I listen to a concert by Mosaic, the St Albans-based chamber choir, I am amazed that they appear to be even better than on the previous occasion.

It’s hard to believe that this group of outstanding amateur singers can continue to improve yet, between the last time I heard them at Christmas and Saturday’s concert of music for Holy Week, the group appeared to have moved even closer to perfection.

By any standard, their programme was a tough one to sing, ranging from Antonio Lotti’s stunning Crucifixus dating from around the end of the 17th Century to the equally fine Evening Hymn written in 1872 by the Finnish composer Elnojuhani Rautavaara.

But the excellent combination of fine voice and attention to the smallest detail by the choir’s director, Nicholas Robinson ensured that the music filling St Peter’s Church in St Albans was of a standard that would be hard to beat.

After opening with Lotti’s Crucifixus, the choir continued with Maurice Greene’s great anthem Lord Let Me Know Mine End and went on to Ralph Vaughan Williams’ Mass in G Minor, where individual members of the choir have the opportunity to sing solo parts, something each one of them achieved with consummate ease and style.

Rautavaara’s setting of the Evening Hymn, although relatively modern, is a complex, yet fine sounding work made harder for the choir because they were singing it in its original Finnish. But the effect was completely compelling.

The first half ended with Plorate filii Israel from Jephte by the 17th-Century Italian composer Giacomo Carissimi, another fine example of music of that period and again a work which the choir handled with great skill to achieve stunning sounds.

Sung by just the tenors, bass and male altos of the choir, Thomas Tallis’s Lamentation of Jeremiah was completely outstanding. The 14-strong group gave a performance which was as fine as you could wish for.

Before Francis Poulenc’s Four Motets for the Time of Penitence, Tom Winpenny, Assistant Master of the Music at St Albans Abbey, played Maurice Dupr�’s Prelude and Fugue in G minor Op 7 no 3.

The work has an extremely tricky prelude and rousing fugue and Tom’s performance did justice not just to the composition, but also to St Peter’s Church’s fine organ.

The Poulenc motets which ended the concert once more demonstrated the tremendous quality of the choir and its versatility.

This was a concert in which Mosaic set a standard which other choirs – not just in St Albans – would find hard to achieve. It is difficult to believe that those taking part are not full-time professional musicians.

JOHN MANNING