IPA: /ˌsɛmɪˈtoʊnəl/
KK: /ˈsɛmɪˌtoʊnəl/
Related to semitones, which are the smallest intervals used in Western music, typically the distance between two adjacent keys on a piano.
The musician used a semitonal scale to create a unique sound in the composition.
Semitonal is formed from "semi-" (meaning half) and "tonal" (from Latin "tonus", meaning tone). The word refers to something that is related to or characterized by half tones or semitones in music.
Think of 'half' ('semi-') tones in music, which helps you remember that 'semitonal' relates to these specific tones.