When observing children playing rhythm echoes with percussion instruments it was noticed that they can repeat a certain number of sounds accurately and that this number increases depending on the children's age and musical experience. It was thought likely that this number has a direct correlation not only with the children's stage of motor development, but also with the development of numeracy, which includes working memory capacity and conservation ability. Moreover, this raised the question of whether we can make an analogy between the children's ability to enumerate homogeneous and heterogeneous sets of objects and their ability to perceive and repeat rhythm patterns that could be made up of both similar and/or different sounds in terms of duration and intensity (accent), even if produced by the same instrument. To test this hypothesis, three groups made up of 10 children--2-4-year-olds (N = 30)--were tested using a traditional task for early numeracy assessment and on their ability to perform a series of rhythm patterns by imitation. As expected, the study found a correlation between number concept development and the performing accuracy of rhythm patterns. Implications for music education strategies and materials are also discussed. (Contains 4 figures and 2 notes.)