FICTA (FALSA), MUSICA. — The expression “musica falsa” certainly existed in the first half of the 13th century, since around 1250 the Pseudo-Aristotle (Magister Lambertus) discusses it and proposes replacing the expression “falsa” with “mutata.” Later, m. f. was preferred. The reason for the “falsity” or “feigning” consists in the fact that, whereas in “true” music one sings according to the intervals indicated by the notation, in “false” music these intervals are changed or altered by lowering or raising them by a semitone through the bemol and the bequadro, placed outside their normal position, namely si: hence falsity because the sign of the mobility of si is moved outside its true place; falsity also because what is sung is not what is written, the key signature being unknown in the Middle Ages; at most, and only rarely, the need to falsify was indicated by adding the bequadro and the bemolle above the note to be altered; normally, however, the singer had to know the rule and apply it even without written indication. The origin of the theory of musica falsa is closely linked with the use of solmization and the development of polyphony. On the one hand, until the introduction of the monosyllables (ut, re, mi, or others), it was neither necessary nor even possible to make “mutations,” that is, in short, to call every semitone mi fa; musica “falsa” would precisely cause mi fa to be sung even when a semitone was not written.
Musical theory prior to about 1030 knows no semitone other than si (natural) do, together with the semitone inherited from the Greeks under the name of synæmœnum, that is, si bemolle, acute, also marked in medieval musical diagrams by the letter S. In practice, however, use was also made of grave si bemolle and of two other mobile notes, mi, which could be bemolle, and fa, which could be diesis. But this should not be ascribed to the practice or theory of m. f., still less to chromaticism in the modern sense; it results from the simple play of the transpositions of formulae or modes and, given the imprecision of medieval modal theory, this play was not brought to light until the transition from writing “in campo aperto” to writing on the Guidonian staff (i.e., the introit “Exaudi Domina vocem meam,” which, if transposed down a fifth, has a mi bemolle at the beginning; if written with final la, it should be sung with fa diesis).
The discussions of medieval theorists prior to the 12th century demonstrate that for them the expression musica falsa, and the concept itself, were unknown. If the division of the monochord produced a sound that could not be inserted into the series of the seven diatonic sounds, the theorist apologized for it as a consideration of purely speculative interest (cf. the De musica of the 11th century, not to be attributed to s. Oddone di Cluny [Gerbert, I, p. 274]: an unusual letter “m” indicates this sound, which constitutes do or fa, “ll mi”; or is interposed between do and re, between re and mi, between fa and sol). Sometimes the theorist simply condemns the displacement of the semitone and calls it “absonia” (cf. Huckold, Musica enchirradia: Gerbert, I, pp. 176–77).
On the other hand, from the examples given in the earliest texts that mention the expression “musica falsa,” it can be seen that this mutation was employed with the aim of obtaining perfect consonances and, above all, of avoiding the simultaneous sounding of the extreme notes of the tritone.
It should be observed, however, that the number of scales, or rather of hexachords, originating from musica falsa does not multiply; according to the most commonly used ones:
begin{array}{l} siᵇ - do - re - miᵇ - fa - sol \ miᵇ - fa - sol - loᵇ - siᵇ - do \ re - mi - faᵇ - sol - la - si \ la - si - doᵇ - re - mi - faᵇ \ mi - faᵇ - solᵇ - la - si - doᵇ end{array}
The importance of this fact of musical practice, also explained by the theorists, should not be minimized; it marks a stage between the more or less rigid diatonicism of Gregorian melody and the appearance of tempered scales; it is directly related to the modal character of polyphonies and music prior to the 12th century and, in many cases, authorizes the
clarifications supplied by certain editors of ancient music concerning notes that, according to classical criteria, ought to be altered.