Musica ficta (from Latin, 'false', 'feigned', or 'contrived' music) was a term used in European music theory from the late 12th century to about 1600 to describe any pitches, whether notated or to be added by performers in accordance with their training, that lie outside the system of musica recta or musica vera ('correct' or 'true' music) as defined by the hexachord system of Guido of Arezzo. In modern usage, the term is often loosely applied to all unnotated inflections (whether properly recta or ficta) that must be inferred from the musical context and added either by an editor or by the performers themselves (Bent and Silbiger 2001).
One common (though not exclusive) use of ficta was to avoid harsh harmonic or melodic intervals such as the tritone, for example the use of a B-flat instead of a B-natural to avoid dissonance with an F in another part. In modern transcriptions of medieval and Renaissance music, ficta are usually indicated by an "accidental" sign appearing above the note. (In modern notation, accidentals are written before the note, not above.) Editors provide these ficta for modern singers, whereas the kind of training given to singers of that time may have made such indications unnecessary.
Medieval and Renaissance singers were trained in a system of hexachords, six-note scales in which each note was given a name - in ascending order: ut-re-mi-fa-sol-la. A hexachord contained only one half-step interval, between mi and fa. The 11th century theorist Guido of Arezzo had designated three types of hexachord: molle ("soft") starting on F, with a half-step between A (mi) and B♭ (fa); naturale starting on C, with a half-step between E (mi) and F (fa); and durum ("hard") starting on G, with a half-step between B (mi) and C (fa). The ficta hexachords were those having a note other than A, E, or B as "mi". For example, a raised F (in modern terms, F-sharp), indicated by adding the ♮ sign, created a ficta hexachord starting on D (D E F♯ G A B) that would be operative until that part mutated into another hexachord where the raised F was no longer desired. Likewise a ♭ sign applied to any note other than B would indicate that it was "fa" in a ficta hexachord; or, when applied to B, that the hexachord was molle rather than durum. Unfortunately, the use of the signs was by no means consistent: it was assumed that a good singer "knew his mi's and fa's," so that the signs were typically only added if the scribe anticipated that singers would be likely to interpret differently otherwise.
The exact performance practice of musica ficta - where and when they were used - is a matter of intense investigation and controversy among musicologists and is likely to remain so for a long time to come. Music theorists from Odo of Cluny in the 10th century to Zarlino in the 16th gave highly different rules and situations for the application of ficta. Thus the controversy is not only among contemporary musicologists; theorists of the Late Middle Ages were never in agreement on the rules of ficta either. Johannes de Garlandia (13th century) and Philippe de Vitry (14th century) both wrote that ficta were essential in singing polyphony because of the necessity of forestalling certain dissonances and properly arranging cadences; but they resisted their use in plainchant. The early 14th century theorist Jacques de Liège, on the other hand, insisted that notes in plainchant needed to be altered with judicious application of musica ficta. !
Contrapuntal treatises of the Renaissance, such as Johannes Tinctoris's Liber de arte contrapuncti (1477) and Gioseffe Zarlino's Le istituzioni harmonice (1588), described resolution at cadences through a major sixth into the octave or the inversion, a minor third closing to a unison, which, unless the other voice already descends by a semitone, necessitates the rising voice to add a sharp (see dyadic counterpoint) (Tinctoris 1961, ; Zarlino 1968, 144–45). At such points, accidentals were in fact sometimes notated throughout this period of history.
- Bent, Margaret. 1972. "Musica Recta and Musica Ficta". Musica Disciplina 26:73–100.
- Bent, Margaret, and Alexander Silbiger. 2001. "Musica Ficta [Musica Falsa]". The New Grove Dictionary of Music and Musicians, second edition, edited by Stanley Sadie and John Tyrrell. London: Macmillan Publishers; New York: Grove's Dictionaries of Music.
- Tinctoris, Johannes. 1961. The Art of Counterpoint (Liber de arte contrapuncti), translated by Albert Seay. Musicological Studies and Documents, 5. [N.p.]: American Institute of Musicology.
- Zarlino, Gioseffo. 1968. The Art of Counterpoint: Part Three of Le istitutioni harmoniche, 1558, translated by Guy A. Marco and Claude V. Palisca. Music Theory in Translation 2. New Haven: Yale University Press. Reprinted 1976, New York: W. W. Norton & Company, Inc.
- Allaire, Gaston. - Ficta Music: http://www.allairefictamusic.com/
- Article "Musica Ficta," in The New Grove Dictionary of Music and Musicians, ed. Stanley Sadie. 20 vols. London, Macmillan Publishers Ltd., 1980. ISBN 1-56159-174-2
- Randel, Don (ed.). 1986. The New Harvard Dictionary of Music. Cambridge, Massachusetts: Harvard University Press, 1986. ISBN 0-674-61525-5
- Arlettaz, Vincent. "Musica ficta, une histoire des sensibles du XIIIe au XVIe siècle". Liège, Mardaga, 2000. ISBN 2-87009-721-1. English summary online: http://www.rmsr.ch/ficta
- Bent, Margaret. 1984. "Diatonic 'Ficta'". Early Music History 4:1–48.
- Hoppin,Richard H. Medieval Music. New York, W.W. Norton & Co., 1978. ISBN 0-393-09090-6