'The Mount Everest of choral music'

Spem in Alium by Thomas Tallis, written in the late sixteenth century in a golden age in English music, is widely regarded as one of the greatest choral works of all. A glittering example of early music, and a vocal masterpiece.

The Bristol Old Vic has commissioned eight new choral works by leading contemporary composers inspired by the original.

They get their world premieres at the weekend as part of the Bristol Proms classical music festival.

Arts correspondent Rebecca Jones has been along to rehearsals to find our more.