o·de·um 
(ō-dēəm, ōdē-)
(ō-dēəm, ōdē-)n. pl. o·de·a (ō-dēə, ōdē-ə)
1. A small building of ancient Greece and Rome used for public performances of music and poetry.
2. A contemporary theater or concert hall.
[Latin ōdēum, from Greek ōideion, from aoidē, ōidē, song; see ODE.]