also: ゲストヴォーカル
noun
guest vocalist; guest singer
A singer who performs as a guest on a recording or live performance, not a permanent member of the group.
from English guest vocal
この曲には有名なアーティストがゲストボーカルとして参加している。
A famous artist appears as a guest vocalist on this song.
ライブでゲストボーカルを迎えて新曲を披露した。
They performed a new song with a guest vocalist at the live show.
Loanword from English 'guest vocal', combining 'guest' and 'vocal'.