This is something that I literally thought of walking home from school listening to "Wolfsong" by Denny Scheindemesser. The piano part at about 04:15 is more than long enough if you're looking for something to listen to and set the mood as you read this.
It was Soul's song before it belonged to anyone else.
It was Soul's song, the gentle rustling of a curtain, carefully placed footsteps on a linoleum tiled floor. It was gentle where he was rough around the edges and harsh where he was fragile. Soul's song was hushed breaths until she stood directly behind him, until she could see him shaking slightly as he pounded and lifted off of the keys. Soul's song was a quiet rustle and a piano bench nearly toppling over as he whipped around and came face-to face with Maka, horror etched across his sharp features.
It was a gentle smile of reassurance.
"Don't stop."
"How did you find me?" His guarded tone, his furrowed brow.
"You play beautifully." She extended her hand and he took it cautiously. "Can I watch for a little longer?"
Soul's song was Maka seated on a piano bench beside him, watching as he poured his soul out for her, unaware of what a momentous event she was witnessing. It was a formed partnership, a blood pact. The first boy she would trust and the last man she would love.
"I won't let you touch my partner."
It chronicled days working in the sun, days spent practicing until everything was perfect. It spelled battles won, bonds formed, bridges built. Soul's song was their battle song as much as it was their song.
Then Soul's song was Crona's song.
It was an invitation accepted, a life given. It was selfless and courageous and cowardly and selfish and loving and kind. It was soft around the edges first, and then increasingly angular and sharp. Crona's song was baseless trust and confusion and pain, but it was also a friendship that surpassed all others, a bond that would outlast space and time. A first note gently pressed, barely heard, fading fast.
"I believe in you."
And then the song was something more than that.
Then it was something more than Soul or Maka or Crona. It was Black*Star's determination and Tsubaki's patience, Kid's honor, Patty's loyalty, Liz's kindness. It was the singing of millions of souls together, the most beautiful music Maka had ever heard. The song was victory and loss, friendship and family in all forms that it took.
But before that, it was Soul's song.