How about this symbolism ? The Well Tempered Clavier is surely one of the most offputting titles in all of music history . Personally , I think the collection should be renamed The Encyclopedia of Human Emotion , for that is surely what these alchemical masterpieces are , interweaving darkness and light , grief and joy in a profound embrace of what it means to be completely human . Written two and a half years after the unexpected death of his first wife , Maria Barbara , and in the year following his marriage to Anna Magdalena , they are beacons of inspiration , inviting us to the full range of earthly experience . TerminologyMajor key a bright or light color sound palette think white wine or champagneMinor key a darker , often more somber or passionate sound palette think red wineClavier any of the keyboard instruments of Bach ' s time organ , harpsichord , clavichord or the emerging forte pianoPolyphony Literally , many voices a style of composition with each part or voice having its own melodyWellTempered a type of tuning system new in Bach ' s time that allowed the possibility of playing in every key . Bach became the first composer to take full advantage of this innovation and became the very first and one of the only composers to write music in every major and minor key . Prelude literally before sounding , preludes were originally improvisatory pieces used to help the performer warm up and get the feeling for the keyboard . The form is open ended , though Bach tended to favor figurated preludes that unbutton a harmonic progression . Fugue a very strictly controlled form in which different voices state the subject main musical theme according to very specific musical rules . The astonishing thing is how much life , joy and dancelike ebullience Bach is able to bring into a very rigid structure . Source twothewelltemperedclavier . html