Undefined has been played on NTS in shows including Annabel Fraser, featured first on 20 October 2019. Songs played include Three Dub and After Effect.

There are multiple artists using this name. It also used as a placeholder name on last.fm:

'Undefined' is the artist that last.fm displays in the event of an error where the correct artist fails to be fetched.

Undefined is a Spanish progressive death metal band. The first Undefined EP is called Saturnism Unfolds and is avalaible to download at http://www.definethenoise.com. "Of Xenoglossy and Saturn", their first LP, was released in early 2008. A breakthrough album in the Spanish metal scene.

UnDeFiNeD is also a Belgian underground band, bringing a variety of urban styles.

Undefined was an Irish psychedelic and indie rock band hailing from Co. Longford