A Dictionary of Music and Musicians/Monotone

MONOTONE (from μόνος, single, and τόνος, a note, or tone). Prayers, Psalms, Lessons, and other portions of the Divine Office, when declaimed on a single note, are said to be monotoned, or recited in Monotone. It is only when ornamented with the traditional inflections proper to certain parts of the Service, that they can be consistently described as sung. [See Accents.]

The use of Monotonic Recitation is of extreme antiquity; and was probably suggested, in the first instance, as an expedient for throwing the voice to greater distances than it could be made to reach by ordinary means.

[ W. S. R. ]