The multipart singing style na tretko is known in different parts of Slovenian ethic territory however this publication is based on the songs that were recorded in Haloze, Styria. In the first part of the monograph Lojzka Merc, Mirko Ramovš and Jasna Vidakovič describe their first encounters with the singing na tretko in Haloze. Urša Šivic defines this singing style from the ethnomusicological point of view on the basis of musical examples. In the second part of the monograph transcriptions of songs performed in the singing style na tretko are published. The transcribed song material is supplemented with the CD Haloško petje na tretko / Na tretko – the Traditional Multipart Singing of Haloze.