The service of matins was structured in three nocturnes, each with three readings and responsories. Thus, during each matins service nine villancicos could be performed, or at least eight if the last responsory was substituted by the "Te Deum", a hymn of thanksgiving reserved for the high feasts. An enormous number of villancicos were written in the Spanish world for such feasts as the Immaculate Conception, Christmas, Epiphany, Corpus Christi, Ascension, Assumption, and other occasions of the Catholic liturgical year. Others were written for important saints' days such as Santiago (St. James), St. Peter and Paul, St. Cecilia, and St. Rose of Lima. In colonial Mexico, villancicos were performed before mass on special feast days as part of a theatrical spectacle that served as lighthearted, comical entertainment which drew large crowds from all sectors of society and included ornate costuming and stage effects to accompany the musical numbers and spoken dialogue. Some have argued that it was the juxtaposition of these disparate, incongruent elements—the sacred against the profane, the refined against the vulgar, the high against the low—that gave the villancico its mass popularity.