Source Verification: Orpheus

Every claim below is either what a named ancient source attests, in its own line or section, or a point where the sources themselves disagree.

What the Sources Attest

Why did Orpheus look back and lose Eurydice a second time?

Neither Virgil nor Ovid explains the motive beyond doubt or longing overtaking him within sight of the surface - Virgil calls it a sudden madness, a moment of forgetting the one condition he had been given. The ambiguity is likely deliberate: a clearly justified reason would make Hades's rule feel arbitrary, while an unexplained lapse makes the loss feel like an ordinary human failure at the worst possible moment.

Source: Virgil, Georgics 4.485-491

How did Orpheus and the Argonauts survive the Sirens?

Apollonius says Orpheus struck up his own song the moment the Sirens began theirs, playing loudly and quickly enough that his music reached the crew's ears first and drowned out the Sirens' voices before the men could be lured toward the rocks. It is the same power that later lets him move Hades, used here for a different purpose: not persuasion, but simply out-competing another voice.

Source: Apollonius of Rhodes, Argonautica 4.891-909

What condition did Hades set for Eurydice's return?

Orpheus had to walk in front of Eurydice on the way back to the surface and not look back at her until they had both fully left the underworld. The condition tests trust rather than obedience for its own sake: Orpheus has no way to confirm she is actually following him, which is exactly what makes the final turn so devastating when it happens.

Source: Ovid, Metamorphoses 10.50-52

How did Orpheus die?

Both Virgil and Ovid have him torn apart by Thracian maenads, women devoted to Dionysus, after he refused to love any other woman following Eurydice's second death. Ovid adds a detail Virgil does not: his severed head kept singing as it floated down the river Hebrus, which later tradition took as proof that his gift outlasted his body.

Source: Ovid, Metamorphoses 11.1-53

Was Orpheus considered a real religious founder, not just a mythical musician?

Yes, in a specific sense: a body of sacred poetry and a set of initiation rites known as the Orphic mysteries were attributed to him, and initiates were promised a better fate after death than uninitiated souls. Whether any historical figure lies behind the name is unresolved, but ancient worshippers treated the myth's underworld journey as the reason he had authority to speak about the afterlife at all.

Source: Ovid, Metamorphoses 11.1-2

Where Accounts Differ

why the maenads killed him

Virgil and Ovid agree on the descent, the condition, and the fatal backward glance, but differ on Orpheus's death: Virgil has the maenads act out of spurned desire, while Ovid frames his refusal of women more broadly and adds the detail of the still-singing severed head.

Sources

Primary sources

Virgil, Georgics 4.453-527
Ovid, Metamorphoses 10.1-85
Apollonius of Rhodes, Argonautica 4.891-909