There isn't a specific musical note that corresponds to the numbers 3, 6, and 9 as they are numerical values and not musical pitches. However, if you're referring to assigning musical notes to these numbers based on their position in a scale, it will depend on the key and mode of the scale being used. For example, in the key of C major, the third note of the diatonic scale is E, the sixth note is A, and the ninth note is D. In D major, the third note is F#, the sixth note is B, and the ninth note is E. So, to assign a musical note to numbers based on a specific scale or key, you'll need to know the order and position of the notes in the scale.