Biographical note

Clément Janequin (ca 1485-1558) was a French composer of chansons, masses, motets and psalm settings. Around 400 of his works have survived. His best known compositions are the large “sonoric frescoes” “La Guerre” (“The Battle of Marignan”), “Le Chant des oyseaux” (“The Song of the Birds”) and “La Chasse” (“The Hunt”). Janequin was a contemporary, and in many respects a counterpart, of Rabelais. He also was a prolific composer of popular chansons and, along with Claudin de Sermisy,  hugely influential in the development of the Parisian chanson.

For more info on his life, see the wikipedia page (based on Grove's, Howard Mayer Brown]. Many who know Janequin's music and esp. his wordly chansons are  amazed that he also wrote  Psalm settings based on Genevan tunes (first 28 Psalms in 1549, and then (augmented to) 82 Psalms in. Before making a crypto-calvinist of him ('converted at the end of his life...') or whatever, one has to consider two things: 

1. Psalms were not exclusively calvinist property at the time (they belonged as much to a more general, francophone (court) culture). The polyphonic settings were explicitlu not for use in Church. The poet, Clément Marot also was a court poet and wrote many frivolous and otherwhise humanly pleasing poems.
2. Psalm settings were becoming popular in the late 1540s and boomed in the 1550s. Du Chemin and Janequin were clever salemsmen. They knew the market.