One of the three earliest attestations of rhapsôidós occurs in Sophokles’ Oidipous Tyrannos 391. If you do not remember the identity of the rhapsode, you may be surprised to read that it is the Sphinx, the bane of Thebes. Why does Sophokles call her a rhapsode?
The answer, everyone agrees, must be sought in her riddle. We actually have a text of it, five lines of hexameter reported by an array of late sources (cf. Mastronarde’s Teubner edition of Euripides’ Phoinissai, pp. 6–7). Another fragmentary text, attributed to Euripides’ Oidipous, was published by Turner in 1962 (fr. 540a of TrGF 5.1). It differs from the better known “vulgate” and seems Euripides’ adaptation. The vulgate riddle was once thought to come from the Oidipodeia, one of the poems in the Theban epic cycle. But since Lesky’s 1963 article Das Rätsel der Sphinx (the fruit of his research for the Pauly-Wissowa RE entry on the Sphinx), most scholars do not believe that the vulgate fully reflects archaic epic diction. Lesky’s article seemed to confirm old doubts whether the Sphinx was a riddling monster in the epic Oidipodeia, and it is now the scholarly consensus that the Sphinx of archaic epic was a brute beast. These doubts had long been fostered by strongly held evolutionary presuppositions about the development of myth, from primitive brute force to intellectual sophistication; by the prejudice that, given its appearance, originally the Sphinx could not have been anything other than a brute monster; and by mere speculation, adopted with the force of fact, about the primary, secondary, or tertiary status of the various motifs of the Oidipous story. This speculation, reinforced by folklore typological parallels, led Edmunds to pronounce the Sphinx “secondary,” and her riddle, “tertiary.” With great confidence the incorporation of the riddle to the story was ascribed to a tragedian (Aiskhylos for Lloyd-Jones) or to a classical epic author (Antimakhos for Lesky).
Lesky’s argument, however, is hardly compelling if one believes that a live tradition of epic recomposition in performance survived into the classical period. We have no reason to expect finished written versions of archaic cyclical poems that reflected an “arrested” stage of thematic, formulaic, and linguistic evolution. Only against the background of such frozen linguistic artifacts could we deem, e.g., the use of allássô in the vulgate riddle for ‘to change’ later than an archaic epic because 1) it does not occur in Homeric poetry 2) and it is first attested with this sense in the Theognidea. Such a view not only presupposes a early fixed Oidipodeia but also a late Theognidea whose growth did not overlap with the development of Theban epic. Neither view comports with the archaic Greek culture of performance, epic and sympotic. In fact, the vulgate riddle bears all the hallmarks of oral poetry. We should hardly be surprised by the traditional character and oral transmission of a riddle “as old as the hills” (to use Kock’s memorable words) and so broadly attested across cultures. The various Greek accounts are formulaic multiforms of one another and the textual items that troubled Lesky (allássô among them) arguably represent reasonable developments of Homeric usage. I believe that they may even reflect oral “inter-textuality,” i.e., the choice by rhapsodes of Theban epic of a turn of expression under the influence of an established passage of Homeric poetry whose diction had reached a sufficiently stable oral form at an early enough time.
If the riddle is oral traditional archaic epic, there is no reason to refuse its ascription to the Theban cycle. Whether this ascription can be narrowed down to a particular thematic subdivision of Theban epic recognizable to the ancients under the title Oidipodeia is not of great consequence. More important is the realization that, as a performer of traditional oral epic poetry, the Sphinx’s designation as a rhapsode was well-motivated and amply justified.