Does playing magical music count as casting a spell?

So in DnD 5e, my bard character happened upon some fragments of a musical composition. When my character tried playing it, it caused some sonic-charged magical effect.

My question is–specifically in the context of conditions like Invisibility where when casting a spell or making an attack drops the Invisibility–does playing this particular piece of music, that happens to have a magical effect, count as casting a spell or making an attack?