Kalmar "bull fiddle" kalma ce ta magana kuma ta yau da kullun don bass biyu, babban kayan kiɗan da ke na dangin kirtani. An yi imanin cewa, sunan “bull fiddle” ya samo asali ne daga yadda aka yi bass biyu daga busassun busassun buhunan bijimai, kuma girman kayan aikin da siffarsa sun yi kama da jikin bijimin. Kalmar "bull fiddle" an fi amfani da ita a cikin mahallin kiɗan jazz da na jama'a.