microintervallen
Microintervals refer to the smallest perceivable differences in pitch in Western music theory. While the diatonic scale is comprised of whole steps and half steps, microintervals represent divisions of these steps, creating pitches that fall between the notes of a standard keyboard. Historically, the concept of microtones existed in various musical traditions around the world, but in Western music, they gained more prominence with composers seeking to expand the harmonic and melodic possibilities beyond the confines of the 12-tone equal temperament system.
The most common way to divide a semitone is into two equal parts, creating a "quarter tone."