Catholic liturgical music refers to the music used during the Catholic Church's worship services, particularly the Mass. It includes hymns, chants, and instrumental pieces that enhance the spiritual experience and support the liturgy. This music is often rooted in tradition, drawing from centuries of sacred compositions. The most recognized forms of Catholic liturgical music include Gregorian chant, which is a form of plainchant, and hymns that are sung by the congregation. Instruments like the organ are commonly used, and music selections are typically chosen to align with the themes of the readings and the liturgical calendar.