The aim of this research is to determine the effect of music instruction with bamboo xylophone as harmonic accompaniment on the singing achievement of second-grade children. Eighty children (N = 80) from four randomly selected classes in two different public schools in the city of Kota Kinabalu participated in this study and they were assigned to two different groups: a control (n = 40) and an experimental group (n = 40). The results indicated that there was a significant difference in the singing achievement of the two groups when the pretest and posttest mean gain scores were compared. In addition, a higher percentage of children improved in the experimental group (30.17%) than in the control group (28.34%). Based on the result of the study, it can be concluded that children can be taught singing with bamboo xylophone accompaniment and that as a harmonic accompaniment, it may improve music instruction.