Ojkanje two-part singing is performed by two or more singers (male or female) using a distinctive voice-shaking technique created by the throat.
It is believed that the ojkanje style originated in the Dalmatian hinterland and spread to other parts of Croatia from there. This style of singing was probably introduced to the Adriatic islands during the 16th and 17th centuries by migrations from the Dinaric region as well as migrations by the Bunjevci, who came from the same area to Vojvodina and Hungary. This polyphonic folk singing tradition is derived from the Dalmatian hinterland, which includes Velebit, Lika, Kordun, and Karlovac. It is a distinctive style of singing melisma that involves a sharp and prolonged shaking of the voice on the syllables "oj" or "hoj." Ojkanje is thought to be a pre-Slavic remnant of Illyrian singing from Dalmatia (modern Croatia, Bosnia and Herzegovina, and Montenegro).
The lead singer holds his or her breath for as long as possible during each song. Melodies are mostly chromatic, tonal, and lyrical topics ranging from love to current political and social issues. Its survival is owed to organized groups of local tradition bearers who continue to transmit the skills and knowledge, participating in festivals throughout Croatia and the world. Traditionally, Ojkanje has been transmitted orally, but audio and video media, as well as organized training within folklore groups, are now playing an increasingly significant role in its transmission. In order for voice-shaking techniques and various two-part forms to survive, however, skilled and talented singers will need to perform and pass on their knowledge to future generations.
Due to the recent conflicts and migration from rural to urban areas, the number of performers has dramatically decreased, thus leading to the decline of many archaic styles and genres of solo singing. However, in the 20th century, the rural lifestyle also has changed significantly, as young people move to cities. They have also overtaken certain traditional practices. As a result, Ojkanje singing has declined.
The Croatian Peasant Party's charitable wing started organizing folklore festivals that celebrated rural traditions at the beginning of the 20th century. The main focus was on traditional dancing, singing, music, and regional costumes. Since then many folklore groups perform in order to preserve Ojkanje singing. Currently, public television in Croatia has broadcast numerous programs on ojkanje groups and reviving the tradition among young people. In many parts of this region, Ojkanje singing is showcased at festivals and cultural events.
References
(https://ich.unesco.org/en/USL/ojkanje-singing-00320) (https://en.wikipedia.org/wiki/Ojkanje)