Plain-song Definition

noun

(music) The unisonous vocal music which has been used in the Christian church from its earliest centuries.

Wiktionary

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

Wiktionary

(music) The simple notes of an air, without ornament or variation; hence, a plain, unexaggerated statement.

Wiktionary

Alternative spelling of plainsong.

Wiktionary