Dai folk songs mostly use the pentatonic scale, and sounds other than the pentatonic scale rarely appear. There are three modal backbone frameworks composed of three-tone sequences. They are [DoMiSol], the ending sound is Gongyin or Zhengyin; [LaDoMi], the ending sound is Gongyin, Jiaoyin or Yuyin; [SolDoRe], the ending sound is Shangyin or Zhengyin. There are also some Dai folk songs that use the modal backbone framework of [SolLaDo].