THE Yorkshire Bach Choir is celebrating its 25th anniversary by holding its most ambitious concert season yet.

Its anniversary season opens on Saturday at the choir's regular home, the church of St Michael-le-Belfry, in York.

And this season sees a particular celebration of the music of Bach, with three of the six concerts focusing on some the composer's most popular and festive choral music.

The actual 25th anniversary concert, on June 26 next year, will present what is arguably the composer's most challenging composition, his Mass in B minor.

On Saturday, December 13, the festive season is marked with his Christmas Oratorio.

In March, the choir performs Monteverdi's famous 1610 Vespers - written for St Mark's, Venice and noted for its ornate solo vocal writing and spectacular instrumental solos.

The opening concert on Saturday includes three of Bach's double-choir motets as well as a motet by one of his cousins, which is being performed for only the second time in this country.

The choir's founder and conductor Peter Seymour said: "This is the most ambitious and exciting season the choir has undertaken, offering substantial challenges but also substantial rewards both for the performers and the audiences."