To celebrate its 450th anniversary, the Royal Grammar School, High Wycombe is giving two concerts centered on two of Walton's larger works: Belshazzar's Feast and Orb & Sceptre. The school called 250 local young people and semi-professional musicians to form a huge orchestra and choir. The concert is held at the Watford Colosseum, Rickmansworth Road, Watford. www.watfordcolosseum.co.uk. Box Office: 0845 075 3993 A gala presentation of Sir William Walton’s magnificent evocation of the dramatic Bible story. The Colosseum provides a grand setting for the oratorio that famously tells the story of the “writing on the wall” that warned Belshazzar, King of Babylon, of his approaching doom. The programme also features Walton’s Coronation March Orb and Sceptre, Handel’s Coronation Anthem Zadok the Priest and Sibelius’ thrilling Violin Concerto, with soloist Tom Aldren, recent leader of the National Youth Orchestra. The 450 Choir and Orchestra brings together over 250 top quality musicians associated with the RGS musical community, including many from their sister school, Wycombe High, as part of the festival celebrating 450 years of the Royal Grammar School in High Wycombe.