unrhythmicallyadv.

1775 J. Steele Ess. Melody & Meas. Speech 188 A speech written down by the help of our notes, according to the bad manner of such a speaker, would appear to be divided unrhythmically; that is, by no equality of metres or cadences.

1845 Illustr. London News 5 Apr. 224/2 The music is graceful, but drags somewhat unrhythmically in the second part of the air.

1932 Musical Times 73 354/2 The passage is often sung badly or unrhythmically, and usually sounds unsatisfactory.

2012 National Rev. (Nexis) 16 Apr. She does put in the work, clapping along unrhythmically like a poorly trained SeaWorld porpoise while the band plays ‘Whiskey in the Jar’.