Two hearts beat as one

Any easy way to complete this or do I have to grind out master recipes 3?

You either have to buy them off the MB or get the master book and make them. You can also have a friend make the music boxes for you.

Since your lodestone says your GSM is 66, I suggest doing some of the Stormblood Collectables (61+) as they are cheap and give a good amount of red scrips. My favorite one that's cheap is the Muudhorn Ring of Slaying.

EDIT #1: A different suggestion I'd like to give is to level your CRP to 50 for Byregot's Blessing; it's a massive increase in Quality and is a great finishing touch to maximize the chance of HQ for a craft. CUL at 37 for Steady Hand II is another great Cross-Class skill to help lower general RNG in a craft.

Not sure if others feel this way too, but personally I loved the story of this GSM quest! Sooooo sweet! :)

Thanks for the suggestions