 Also around this time, Italian flagellants developed the Italian folk hymns known as spiritual laude.Between 1317 and 1319, Marchettus of Padua wrote the "Lucidarium in artae musicae planae" and the "Pomerium artis musicae mensuratae", major treatises on plainchant and polyphony, expounding a theory of rhythmic notation that paved the way for Trecento music (Italian "ars nova").Around 1335, the "Rossi Codex", the earliest extant collection of Italian secular polyphony, included examples of indigenous Italian genres of the Trecento including early "madrigals", "cacce", and "ballate".