Following the allegorical prologue extolling the triumph of Minerva, Cupid, and Venus over the ravages of war, the first act immerses us in the realm of heroic Greece. The main plot revolves around the brothers Castor and Pollux. After Castor’s untimely demise in battle, his heartbroken lover Télaïre implores his immortal brother Pollux to intervene. Pollux selflessly offers to take Castor’s place in the Underworld, enabling his return to Télaïre. Torn between love and duty, Télaïre initially refuses Pollux’s sacrifice. In a moment of compassion, Jupiter grants Castor immortality, allowing him to remain on Earth with his beloved. Pollux is also released, and as a testament to their eternal bond, the constellation Gemini ascends into the celestial realm.

Rameau’s masterful composition in Castor et Pollux showcases his unique musical language. Each dramatic moment is vividly portrayed through elaborate harmonies, diverse instrumentations, and demanding vocal lines. The opera’s innovative and expressive nature, which characterized both Rameau’s brilliance and polarizing style, continues to captivate audiences to this day.