Stone: (for this, imagine you can sing :3). When he first heard you singing, he thought that Maggot came back down, because to him, your voice sounded like an angel's chorus. But when he discovered that it was you, he was pleasantly surprised! (I'm basing this next part off of Zeddyzi's art). He would get out his violin and begin playing along to your melody! After that, y'all would play together all the time, even write some music together!
Vinnie: (for this, you play piano :3). Vinnie first heard you play when you found a discarded but still good piano in one of the alleys. She was surprised that you found the piano, much less that you knew how to play it! But she was politely silent until you finished, to where she gave you the biggest round of applause. Now you play for her whenever you can, as it gives both of you joy :3
Skipp: (clarinet, since my friend wouldn't stop bothering me to add it somewhere). He first thought he was dreaming when he heard you first play the clarinet. But then you finished, and he knew that he wasn't. He ran up to you and asked all about your instrument, how you played it, ect ect. Y'all start playing the clarinet and his ukulele together, and it sounded pretty good!
Ditch: (Trumpet). He didn't know what the sound was at first. But then he found you in one of the more hidden rooms of the warehouse, and didn't reveal himself as he heard your beautiful playing. He never did reveal himself, and now he just watches you as you play in secret.
Pebble: (You play the violin ;3). Pebble had heard Stone play the violin a few times before, but never as smoothly or as beautiful as you did. When he discovered you, he just sat down next to you and listened as you played. After you finish, he pulls you into a hug and requests another song. Now you use that method to make him go to sleep.
