Greek and Roman rhetorical treatises provide many observations on the topics and aims of prose introductions (προοίμια, exordia, principia), but have little to say about poetic introductions and practically nothing about their formal elements. The purpose of this article is to explore the forms that underlie the beginnings of Greek poems. No system of classification can provide an exhaustive account of the various ways in which Greek poems open, but a few formal patterns do predominate, and in order to discuss them I have divided the openings of Greek poems (whether epic, dramatic, or lyric) into four main types: narrative, dramatic, discursive, and hymnal. The narrative opening begins by telling about an event without any prefatory statements. The dramatic opening presumes a situation in which the speaker of the poem finds himself; although it naturally occurs in drama, it is also found in non-dramatic poetry, increasingly in the Hellenistic period. The discursive opening sets forth a proposition, either explicitly or implicitly, for which it argues; common forms include comparisons and contrasts, priamels, gnomes, and justifications of the poet's role. The hymnal opening, the earliest and most pervasive of these types, really comprises two kinds of hymns, rhapsodic and cultic. After a brief review of each type, we shall conclude with examples that illustrate innovative combinations of them.