ataktische
Ataktische is a term used in German music theory to describe passages or styles that deliberately avoid a regular metrical structure. Derived from takt (measure, bar) with the prefix a-, it literally means “without meter” and is applied to rhythm that does not consistently align with a fixed beat pattern. In ataktische passages the timing may feel flexible, unpredictable, or non-periodic, and phrases can be grouped without consistent bar lines or regular accent schemes.
In practice, ataktische music may exhibit irregular grouping of notes, irregular metrical accents, cross-rhythms, or tempos
The concept is used primarily in German-language music literature. In English, scholars frequently describe similar phenomena