Written by Johann Sebastian Bach between 1738-1742, it is a collection of 24 preludes and fugues in all major and minor keys, following the same format as Book 1 written in 1722.
It demonstrates Bach's ideas of well-tempered tuning, where all keys have a similar level of resonance and musicality due to the tuning methods used. This enabled composers to write in any key.
Musically, the collection draws inspiration from Baroque, French, Italian and German styles. It includes incredibly complex fugues as well as light dance-inspired movements.
Many preludes and fugues are paired to explore contrasting characters (e.g. Prelude No. 5 is gentle while its Fugue is lively). Others explore experimental and forward-looking ideas.
Its composition for a solo keyboard instrument (typically piano or harpsichord today) makes it a seminal work for pianists. It explores the capabilities of these instruments.
