DIATONIC,, a musical term signifying literally "through the tones," otherwise music in the case of which the notes employed are confined to those of the key, major or minor as the case may be, in which it is written. Hence diatonic music gives a general impression of strength, simplicity and solidity as distinguished from the more restless and poignant character of that in which notes from foreign keys are introduced by accidentals (q.v.).