Tests of musical ability in children have relied on diverse conceptions of what musical abilities are. Recent investigations suggest that such conceptions can be seen as socially constructed and differ between cultures, sub-groups, and individuals. Based on a previous study on conceptions of adult musical ability, we designed a questionnaire targeting musical behaviours of 3-6-year-old children. 922 German adults who regularly spend time with children assessed how often a musical child would show these behaviours. Principal component analysis revealed four components of childhood musical ability: musical communication, enthusiasm and motivation, analytical understanding of music, and musical abilities in a narrow sense. The importance assigned to the components differed depending on musical expertise: Participants with higher expertise rated analytical music skills as significantly less important. Results suggest that ecologically valid tests of musical ability in childhood should cover a wide range of skills and observable behaviours.