JS Bach's role in the development of Equal Temprament was vital. Equal Temprament is a type of tuning, which over time has become standardised on almost all instruments in Western Classical Music. Instead of notes named eg. Eb and F sharp having different pitches, equal temprament involved finding a middle ground. JS Bach not only fine- tuned the principles, but also brought it to prominence through his collection of Preludes and Fugues, one in each key of Equal Temprament (The Well-Tempered Clavier).