Gregorian chants are divided into three types based on the number of notes sung to each syllable. "Syllabic" chants mostly have one note per syllable. In "neumatic" chants there are mostly two or three notes per syllable, while "melismatic" chants have lots of notes for one syllable. Some of the chants are recitative and some are free melody. When two choirs stand in different parts of the church and sing alternately these are called "Antiphonal chants". "Responsorial chants" are ones with a refrain sung by the choir, which alternate with a psalm verse sung by a soloist.