Ivan Hewett examines the chord of C major as found in Terry Riley's In C to test the idea that harmony is a reflection of history. He's joined by musicologist Pwyll ap Sion and pianist Joanna MacGregor.

Music is never created in isolation - it's conceived in relation to what's going on around a composer in terms of personal and historical events, new technologies, new ideas and artistic endeavours in other fields. In this series, Ivan Hewett is looking at five very different chords which amply demonstrate the concept that harmony is a reflection of history.

Each programme is a bite size portion of rich musical and historical investigation - and each chord has had far reaching influence on other music and is emblematic of its era.

In 1964, the Californian composer Terry Riley wrote a piece which changed the face of classical music - and it was entirely based on the chord of C major. The piece is called In C and its composition is said to mark the beginning of the Minimalist movement in music. After the complexity of the other chords in this series, this final episode explores how In C reflects the era in which it was written and, in particular, how employing the seemingly simple chord of C major was so appropriate for its time.

Ivan Hewett is a writer on music for the Daily Telegraph, broadcaster on BBC Radio 3, and teacher at the Royal College of Music.
Have a listen at http://www.bbc.co.uk/programmes/b088974y