A term and acronym used to distinguish musical tunings calculated by ratios of large numbers, from those with small-integer terms and/or an audible property of containing many very consonant intervals. The latter is a special case of RI called "just intonation" or JI, whereas RI is the more general category of tunings which includes all JI tunings.
A notorious example of an RI which is not synonymous with JI is the tuning of the Hammond organ, which see.
The rational-intonation acronym RI is not to be confused with the Sanskrit syllable "ri", which is used in Indian music and music-theory.
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