plainsong

noun

1. (countable, uncountable)A form of monophonic chant in unison using the Gregorian scale, sung in various Christian churches.
2. (countable, uncountable)A cantus firmus or theme chosen for contrapuntal treatment; so called because often an actual fragment of plain-song.
3. (countable, uncountable)The simple notes of an air, without ornament or variation.
4. (broadly, countable, uncountable)A plain unvarnished statement, without exaggeration.