| Role | Voice Part | Classification |
|---|---|---|
| Jason | Tenor | L |
| Female Narrator/Atalanta/Siren/Medea/Lamb | Soprano | F |
| Male Narrator/Orpheus/Lamb | Baritone | F |
| Chiron/King Pelias/King Aeetes/Dragon | Bass-Baritone | F |
| All combined roles are as specified in the score. | ||
| Minimum Chorus: No chorus |