Alleluia and Oratorio

Oratorio and alleluia are semantically related in religious song topic. In some cases you can use "Oratorio" instead a noun "Alleluia".

Oratorio noun - A musical composition for voices and orchestra based on a religious text.

Alleluia and oratorio are semantically related in chant topic. You can use "Alleluia" instead a noun "Oratorio", if it concerns topics such as paean, religious song.