Definition of musica ficta in English:

musica ficta

Pronunciation /ˌmyo͞ozikə ˈfiktə/ /ˌmjuzɪkə ˈfɪktə/

noun

Music
  • (in early contrapuntal music) the introduction by a performer of sharps, flats, or other accidentals to avoid unacceptable intervals.

    ‘Two of the most famous authors of this period, Walter Odington and Philippe de Vitry, do not approach musica ficta from the standpoint of attraction accidentals.’
    • ‘That's what so-called ‘musica ficta’ threatens to do to Ockeghem, Busnoys, Josquin, and Gombert.’

Origin

Early 19th century Latin, literally ‘feigned music’.