This article is about modal frames in music, for modal logic see Kripke semantics. In music a melodic mode (van der Merwe 1989, p.102-103) or modal frame is one of "a number of types permeating and unifying African, European, and Americansong" and melody (Middleton 1990, p.203) including parlour music. "Mode" and "frame" are used in this context interchangeably. Melodic modes allow melodies which are not chord-based or determined by the harmony but instead by melodic features. A note frame is a melodic mode that is atonic (without a tonic) or has an unstable tonic.
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