Vocality or special vocal effects are vocal or vocally inspired devices including guttural effects, interpolated vocality, falsetto, blue notes, Afro-melismas, lyric improvisation, and vocal rhythmization. All of the listed devices are attributes of African vocality and are used to emotionalize vocal and instrumental performances in African American vernacular music.[1]
Guttural effects include screams, shouts, moans, and groans. Shouts may be intoned or nonintoned (definite in pitch/sung or indefinite in pitch/spoken). Interpolated vocality is the addition of new vocal sounds or texts (interpolated verbalism) to a song while lyric variation is derived from or embellishes existing lyrics.[1]