Sometimes the children in older Primary are ready to learn a harmony part or companion song. Here is one idea:
I teach this separately from the original hymn, then ask the children if they can sing Choose the Right while I sing the companion song. Challenge them not to pulled off the hymn by what you are singing. It makes them beam with delight when they can do it.
Then, ask the children if they can sing the companion song and not get pulled off while you sing the original hymn. You might want to stop there, and revisit the companion song the next Sunday (it will go deeper into the memory that way). After a few more exposures, split the group with one of the teachers or presidency members leading each group, and have each sing either the hymn or companion song. Now switch and have each group sing the one they didn’t sing the first time.
Sometimes the older children appreciate the song even more when they tackle a harmony part or companion song. It’s a challenge and it can be fun for them!