With a comma, comma, comma, comma, comma chameleon.
Composition copyright is there to identify who owns the copyright on a composition of a track or album. The composition refers to the notes, melodies, phrases, rhythms, lyrics, harmonies, etc. The original creator of the piece.
If you’ve uploaded an album to RouteNote where only one track is a cover and the others are self composed, you should put both the original performing artist of the covered song and the artist who composed the rest in the C line. Or if you’ve uploaded an album where there were two songwriters involved, you can credit both names within the C line.
You should separate two or more names/artists in the C line by a comma, like this:

So no need to leave anyone out!
If you’ve got any further queries or concerns, just let us know at support@routenote.com!
Here’s a little more info on C lines and P lines in the video below…
See also:
What should I put in the C line if my release is a cover?
Should I credit the composer in the C line of a classical release?
Can I credit my label in my C line/P line?