Of course there is no singing without harmonics, because every singing tone contains harmonics. I classify it as overtone singing when the musician’s intention is to provide overtones with their own musical role.
It is important to me to define this from the perspective of the singer, because not everyone perceives the overtones without practice. Transitions from speech to targeted overtones can be fluid (hearing test). According to a study by the University of Heidelberg people hear the overtones very differently, so that even trained musicians do not always immediately recognize the overtones in the voice. Overtone listening is trainable.
Classification by Cultures
Classification by Sound Character
Overtone melodies are the most noticeable, but not the only form of overtone singing. Overtones can be used musically without creating melodies: for tone effects, intonation, resonance and as a basis for scales. Examples are Tibetan monk songs, Barbershop or the Sardinian canto a tenore. The weaker the overtones are compared to the overall sound, the more difficult it is to assign them to overtone singing.
Overtone Sound Scapes
For the sake of completeness, I would like to mention singing styles that are erroneously referred to as overtone singing. These are singing techniques called throat singing. Throat singing is used in music ethnological terms, especially in older literature, for throaty, rough songs and singing with narrowing of the larynx and has nothing to do with overtone singing. Only since the 1990s throat singing (as a translation of the Tuvan word khöömej) has become synonymous with Central Asian overtone singing. You have to be careful what kind of throat singing is meant, especially when translating from English. When reading recent literature, one should pay attention to whether the author has carefully researched.
- Biphonic singing techniques other than overtone singing
- Yörük throat playing – Anatolia
- Throat singing of the Inuit – Canada
- Joik of the Sami – Lapland
- Rekuhkara of the Ainu – Japan