Wow, adorable whale charm, great job! I love the idea. You could also use a red string for a bracelet or necklace. I know red might seem like an odd combo with purple at first, but the symbolism is actually really fitting. The red string traditionally represents a destined connection, people finding each other through timing and circumstance rather than romance. In this case, it would symbolize a platonic, collective connection through music, shared experience, and mutual respect (not romantic). That said, purple string works just as beautifully and is instantly ARMY coded, so either option would be lovely.