Kudüm is one of the most fundamental rhythm instruments in Turkish classical music. The person playing it is called kudümzen. In the Rumi music (Mevlevi music), it is one of the four main instruments along with ney, rebab (Turkish: rebap), and halile (cymbal of Turkey).
It consists of a pair of small, hemispherical drums. Traditionally kudüm was played in religious ceremonies; in a secular context, like in Ottoman military band (mehter music), its slightly bigger cousin nakkare (Turkish) is played.