This puzzle was easy to get to but hard to solve.

With six word and a six-letter meta puzzle, I had to be on the right track.
That the puzzle is in the key of C gave me more confidence. And that it was a C meant it was probably a DO RE MI type of thing.
I looked for things at the end. HEEL probably went with SOL because heel and sole. That became obviously wrong the more I went along.

What if I tried to find notes everywhere? Would that help?
No.
Back to the original.

OK way more sense. The letters at the end of each long word.
RE MI SOL TI LA DO
CMaj scale:
DO – C
RE – D
MI – E
FA – F
SOL – G
LA – A
TI – B
So
D E G B A C
There you have it! DEGBAC
I submitted CHORDS, but I know that’s not right.