We have cruised Musica the sister ship. You don't say how many night cruise your on but there will typically be a couple of Formal Nights & the rest smart casual. My nephew, 16 at the time & about a dozen cruises behind him, was bored to tears & that was at Christmas when the ship should be in a upbeat mood. Sorry if that was not the answer you wanted to read but it is a honest response. Regards Wilba.
I travelled at Easter on the Orchestra and the dress code was a mixture of formal and casual/informal. I travelled with 15 and 16 years old but unfortunately MSC do not really cater for teenages and we found that most evenings we would rent a movie and watch it in the cabin.