Paganism is an umbrella terms describing a wide variety of Earth-centered spiritual practices and traditions. These are often amalgams of reconstructed practices from pre-Christian societies and new traditions formed over the course of the 20th and 21st centuries. Pagans are wildly diverse in their beliefs and practices, but some commonalities between most practitioners include a belief that the Earth is alive and divine, reverence for the interconnectedness of all things and the cyclic nature of life and death, expressions of divinity across and beyond gender (often with a focus on the feminine), personal magical practice, celebration of seasonal and/or historical holidays such as Solstices and Equinoxes, and personal spiritual autonomy. There are many different paths within Paganism, including Witches (Wiccan and other), Druids, reconstructionists (practicing historical religions), eclectics who draw from multiple traditions, and many others. Pagans are not Satanists or devil-worshipers, and generally don't believe in those figures at all.
"Ritual" is often seen as a scary word in modern US American culture, but within Paganism it is the word we use to describe structured worship and ceremony. Rituals can take a wide variety of forms, but often begin with the creation of sacred space, progress through invocations of the entities such as the elements, deities, ancestors, and spirits, and go on to some sort of guided meditation, divination, theatrical performance or recitation, embodied activity or craft project, music, discussion, magical working, or ritual meal. Following this, the invited entities are devoked (asked to leave), and the sacred space is disassembled. Rituals are generally led by one or more facilitators, (called priestesses, priestexes, or priests) and are highly participatory, with all participants taking an active role in the procedings.
The music used in Pagan ritual is extremely diverse, but the Pagan movement has given birth to a genre all its own. Modern Pagan chant is influenced by a wide variety of sources including Celtic folk music and US American rock and singer-songwriter genres. It is a participatory tradition, meaning that the goal is not to produce a flawless performance, but instead to include as many people as possible in the music-making. Chants are short and simple to facilitate easy learning and accessability to all levels of musical experience. In ritual, chants are often sung over and over for extended periods of time, gradually gaining set or improvised harmonies and contrasting parts as participants find the level of participation that feels most satisfying to them. As a living oral tradition, there are often multiple versions of any given chant.