Introit and Piece of music

Introit noun - A composition of vocal music that is appropriate for opening church services.

Piece of music and introit are semantically related. In some cases you can use "Piece of music" instead a noun "Introit".

Piece of music noun - A musical work that has been created.

Introit and piece of music are semantically related. Sometimes you can replace term "Introit" with "Piece of music", this terms are similar.