arrhythmous
/əˈrɪðməs/Definitions
1. adjective
Lacking a regular rhythm; irregular in rhythm, especially in music or poetry.
“The composer’s experimental use of arrhythmous beats added a sense of uncertainty to the piece.”
2. noun
A musical composition characterized by a lack of regular rhythm.
“The arrhythmous piece was a departure from the traditional sonata form.”