Music permeated every walk of fifteenth-century life, from popular and aristocratic entertainment to religious and civic ritual. Music was sung or performed on instruments, executed by individuals or groups, played by ear, improvised or read from notation. During the 1430s and 1440s, the traditionally rather learned and esoteric isorhythmic motet was eclipsed as most prestigious genre by the so-called cyclic Mass, grouped settings of texts from the Ordinary of the Mass. The smaller-scale music also tended to be composed rather differently, with simpler vocal parts conceived together rather than as successively superimposed layers. Range of musical style is also surprisingly wide, despite a general tendency towards a tuneful, semi-popular manner, there are also a number of far more refined and sophisticated pieces, especially among the more austere devotional carols of the later years of the century. The basis for academic study of music and the ultimate source for most of the speculative treatises was Boethius' treatise De institutione musica.