OCD(3) s.v.
Strabo 10.4.19 gives the name as Thales, but Thaletas (in e.g. [Plutarch], de musica passim) seems the more authentic version.
[1] cf. theta 22, where (presumably) this same Thaletas is said to come 'from Knossos' (in Crete). In the present entry Illyrios has been conjectured to be an error for Elyrios, i.e. from Cretan Elyros; if so, as Bernhardy noted, one would then delete 'or'.