Evidence for auletic harmateios nomos is limited to three passages: Ps.-Plut. de mus. 1133E-F (which is obscure); Plut. de Alex. fort. aut virt. 335A (where the name of the nome is probably erroneous), and Eur. Or. 1384 (harmateion melos), which the scholia interpret in eight different ways. Identification with any other novmoi seems unfounded. Since both ancient and modern explanations of harmateios nomos are far from being always the same, the paper aims at analyzing all the opinions expressed so far, in order to distinguish among certain facts, probable hypotheses (attempting to make some additions to this category) and unfounded speculations. It can definitely be established only that harmateios nomos was somehow connected with a chariot and that it was a piece of mournful aulos music. Taken together, these two facts can be explained by ascribing to the chariot nome some sorrowful mythical subject, in which a chariot occurred. Onomatopoeic imitation of syrigmos of a rushing chariot in aulos music is highly probable. With so few facts to build on, the definite subject as well as peculiarities concerning pitch (high), mode (Phrygian), tempo (swift), rhythm (dactylo-anapaestic? dochmiac?), occasion for performance (agonistic or ritual) of harmateios nomos can be hypothesized, but not established with certainty. Yet the number of various accounts on this nome expressed in antiquity and in modern times can be substantially reduced.