You know all about accidentals? Now it is time to learn quarter tones.
Quarter tones are used in contemporary music or to adapt eastern music to western music notation.
Quarter flat lowers the pitch by a quarter tone.
Quarter flat raises the pitch by a quarter tone.
Three quarter flat
Three quarter flat lowers the pitch by a 3 quarters tone.
Three quarter sharp
Three quarter flat raises the pitch by 3 quarters tone.
Summary of quarter tones
Note that there are several symbols for each quarter tones notation:
Quarter tone scale
Below you can hear a quarter tone scale.