 Gregorian chant supplanted all the other Western plainchant traditions, Italian and non-Italian, except for Ambrosian chant, which survives to this day.The native Italian plainchant traditions are notable for a systematic use of ornate, stepwise melodic motion within a generally narrower range, giving the Italian chant traditions a smoother, more undulating feel than the Gregorian.Crucial in the transmission of chant were the innovations of Guido d'Arezzo, whose "Micrologus", written around 1020, described the musical staff, solmization, and the Guidonian hand.