musica recta

Term used in the 14th and 15th centuries to mean the notes of the gamut as projected by the three kinds of hexachord, that is, the white-note scale from G to e'' but including B flat as well as B natural (or, with a key signature of one flat, including E flat as well as E natural, and so on). Since this was the normal scale, the note B could be sung either flat or natural without special indications. This concept is important for editorial accidentals and musica ficta: where there is an alternative, musica recta should be operated before musica ficta.