structural:expansion, stylistic:tone
Cantus firmus masses

Prior to Josquin's mature period, the most common technique for writing masses was the cantus firmus, a technique which had been in use for most of the 15th century. Josquin used the technique early in his career, with the Missa L'ami Baudichon considered to be one of his earliest masses. This mass is based on a secular tune similar to " Three Blind Mice ". Basing a mass on such a source was an accepted procedure, as evidenced by the existence of the mass in Sistine Chapel part-books copied during the papacy of Julius II (1503–1513).

Josquin's most famous cantus firmus masses are the two based on the " L'homme armé " (lit. ' the armed man '), a popular tune for mass composition throughout the Renaissance. Though both are relatively mature compositions, they are very different. Missa L'homme armé super voces musicales, is a technical tour-de-force on the tune, containing numerous mensuration canons and contrapuntal display. Throughout the work, the melody is presented on each note of the natural hexachord: C, D, E, F, G and A. The later Missa L'homme armé sexti toni is a "fantasia on the theme of the armed man." While based on a cantus firmus, it is also a paraphrase mass, for fragments of the tune appear in all voices; throughout the work the melody appears in a wide variety of tempos and rhythms. Technically it is almost restrained, compared to the other L'homme armé mass, until the closing Agnus Dei, which contains a complex canonic structure including a rare retrograde canon, around which other voices are woven.