In this study, we explored associations between perception of musical features (pitch, tonality, timing, timbre, and loudness), vocal abilities (singing accuracy, melodic achievement, and rhythmic performance), and cognitive levels (reading accuracy and comprehension, grammar, and math) among children ages 6 to 12. Musical perception abilities were measured using the Implicit Tonal Ability Test. Vocal abilities were measured using the Vocal Musical Ability Test. Cognitive levels were measured using standardized Dutch performance tests on academic skills. We investigated which factors (age, gender, cognitive levels, school type, music perception abilities, and participation in music education) predict vocal abilities and how these abilities differed by age. Results showed that singing accuracy was best predicted by gender, math level, and music perception abilities. Melodic achievement was best predicted by age, school type, math level, and music perception abilities. Rhythmic performance was best predicted by age, instrumental music education, and music perception abilities. Regardless of their age, differences in singing abilities between children were large. We advise teachers to provide activities in which repetition and prediction of patterns, scales, all intervals, and intonation are practiced, including transposing melodies and repeating rhythmic patterns.