This paper contends that Horace's comparison of his completed poetic monument to pyramids at the end of Odes 1–3 is both figurative and literal insofar as we possess ample art historical, literary and papyrological evidence from antiquity for the stacking of an appropriate number of book (sc)rolls in ‘pyramidal’ form. Most notable in this regard is the dedication to Delian Apollo of a triangular casket containing the ten books of Aristarchus' edition of Alcaeus, whose resonances with the Pythagorean τετρακτύς, and implications for Horace's own oeuvre, are duly explored.