Final answer:
The Chorus is responsible for singing the odes in Greek drama, which serve as narrative commentary, thematic reflection, and scene transitions.
Step-by-step explanation:
In Greek drama, the group responsible for singing the odes is known as the Chorus. These odes typically serve several roles within the narrative of a play: they provide backstory, comment on the action, represent the collective voice of society or the polis, break up the scenes or acts, and offer reflections on the thematic elements of the play. The Chorus could be seen as an actor within the play that guides the audience through the dramatic events, echoing the concerns or emotions that the audience might have, and contributing to the moral and philosophical fabric of the story.