They have known from the first few days attending the School of Friendship that ponies are musically inclined. Songs they’ve heard are usually about something important like a lesson or to explain how to bake in Professor Pie’s case. Yet—around Ponyville they notice ponies singing songs about small things. Something else they notice is that random ponies who join in seem to be able to perfectly add to the song lyrics.

How are ponies able to sing a random song together out of the blue? And, where does the music accompanying the song come from?

When Sandbar can’t give a solid answer, even though he’s a pony and has had musical outbursts, they decide to look further into the topic for a project assigned to them.