pdq don't forget the noises produced that aren't harmonically related to the note being played, but do contribute to the overall sound heard which are characteristic of the instrument e.g. the breathiness of a flute, the string noises on a guitar, the bow sound on the string, box noises, attack (Tongued/non tongued; plucked/bowed) - all these contribute to the overall sound of an instrument which is variously described as tone or timbre. And did you mean formant? Hope this doesn't seem nit picking.

Stu