What is temperamperament

Musical temperament gives the exact position of the notes within an octave.

Imagine that the 12 notes of an octave are 12 beads strung on a string, exactly equidistant from each other, i.e. 12 equal semitones. This is the model of equal temperament most commonly used today. The unit of measure for the pitch of the notes is the Herz (Hz) and the distance between the notes is the cent (c). In equal temperament, the distance between the semitones is exactly 100 cents.

Centuries earlier, however, this was not used. We know of several documented tuning systems that were quite different. Shifting the notes up or down even slightly changes the sound and usability to a great extent.