Adrianna (12) played three songs. We don’t know the name to the first song; it is a mashup of a tune she heard online somewhere and her own composition, the second song she also heard online on a fan-made animation of Pinkie Pie that she taught herself to play by ear, and the third is Bonetrousle, her arrangement of the song by the same name from the UnderTale video game.
Bree (7) played Cheerful Dance and Our Grand Finale. Their duet is called Fallen Down and is also from the UnderTale video game.
The duet was by ear. For Adrianna’s songs, some music portions were found on the app MuseScore and a bulk was also arranged by Adrianna/by ear. Bree’s songs were with music, though I think she relies on her ear quite a bit when playing, too.