original song; original piece of music
Refers to a musical work created by the artist or composer themselves, as opposed to a cover or arrangement. Can also mean music composed for a particular event or purpose.
At her live performance, not only famous cover songs but also original songs were performed.
The original music written specifically for this movie became a topic of conversation.
Compound of オリジナル (orijinaru, from English 'original') and 曲 (kyoku, 'song' or 'piece of music').