Alteration

Contents 1 Definition 2 Semitone alteration 3 Microtone alteration 4 See also

Definition

Alteration in music is the changing of a basic tone, by raising or lowering it's pitch with one or two semitones or other microtones, thus enhancing the diatonic to a chromatic system.

Semitone alteration

In notation the following signs are used for this:

• Sharp, to raise the pitch by one semitone
• Flat, to lower the pitch by one semitone

• Double sharp, to raise the pitch by two semitones
• Double flat, to lower the pitch by two semitones

• Natural, to correct any of the previous alterations

Microtone alteration

There is is no general standardization as to how to notate the finer-than-semitone intonations sometimes prescribed by composers or played by performers. In different books and scores, various alternatives have been used. In any case, notation does allow for precise quarter tone alteration and finer microtones such as shrutis and commas, as well as completely different tuning systems such as the Huygens-Fokker 31 tone system.

See also

• Outline of basic music theory
• Special:Browse/Alteration - browse this page to find whiteboards treating alteration.