Do you have same performers on all the tracks? Or each track different?
On the left side, if you want to set the same Orchestra on everything, tick the blue tick at the top of the column to tick all tracks and use “Batch-add a relationship to recordings” to select artist \ orchestra.
To do just one recording use the Add Relationship under that one recording.
If not orchestra, you can select “instruments” in that same box. And then add details of that instrument.
the easiest way to make this change (without having to individually edit each recording) is to edit it via the release editor (the Edit tab), go to the Tracklist tab therein, and change the artist credits to the performers (as credited on the front or back cover), on the Recordings tab, check the “Copy all track artist credits to associated recordings” box, enter the edit, then cancel the tracklist edit
you’ll then do the same for the composer on the track artists, but don’t check the box on the Recordings tab this time
one other change, the release title shouldn’t have the composer or performer names; those should only be in the artist field (in 99% of cases, see the page on Release and Release Group Titles for more detail)
(if it might help, I can add images later, but I’m currently away from my computer…)
It is used from the release page, on the sidebar, under “loujine GM tools” - works only if the performers are available as a relationship already for the relevant recordings, but I guess they are here.