plainchant

noun

1. 1

   A form of monophonic chant in unison using the Gregorian scale, sung in various Christian churches.

2. 2

   A cantus firmus or theme chosen for contrapuntal treatment; so called because often an actual fragment of plain-song.

3. 3

   The simple notes of an air, without ornament or variation.

4. 4

   (by extension) A plain unvarnished statement, without exaggeration.