Discant is a word that is not commonly used in everyday language, but it does have synonyms that people may be more familiar with. Some of these synonyms include descant, counterpoint, melody, and tune. All of these words refer to a musical or vocal line that is played or sung in harmony with the main melody. Descant, in particular, is often used to describe a high-pitched harmonious melody that compliments the main tune. Any of these words can be used to describe the addition of a secondary, complementary melody to a piece of music or song.