INDEX CANTORUM celebrates its 15^th anniversary of its first performance with a concert in Winchester Cathedral.  The programme theme, ‘Power and Glory’, is an exploration of the role of music, not only as a force to express ideas and emotion, but also for the way in which its content and direction as a consequence have been influenced by political or religious needs.  Each of the pieces in the programme has a tale to tell, whether conceived as a statement of power reflecting the thinking of the age, or written as an expression of a desire for change. The main feature of the programme is Tallis’ motet, ‘Spem in alium’, purportedly written in response to the Duke of Norfolk’s challenge for an Englishman to upstage an earlier grand motet written by a continental composer and performed for Elizabeth I.  To this day, Tallis’ motet in 40 parts eclipses its rival, and has become one of the pieces for which he is most remembered.  Winchester Cathedral provides the ideal setting and acoustic for the scale of 40 independent vocal parts