無む伴ばん奏そう

noun which may take the genitive case particle 'no'

unaccompanied; a cappella

Used in music contexts to describe a performance without instrumental accompaniment, especially for vocal music.

• 合がっ唱しょう団だんが無む伴ばん奏そうで歌うたを披ひ露ろうした。

  The choir performed the song a cappella.