Most kids aren’t interested in classical music and that probably shouldn’t be the default for so many teaching methods. If you want kids to play, make it fun. Teach them the music they listen to.

When my kids were taking music lessons the teacher would sometimes try to talk to me after the lesson and tell me what they did and wanted to discuss with me what to teach next and my reply was always the same - why are you having this conversation with me? It’s my kid that you have to keep engaged. I’ll keep paying for lessons as long as my kid wants to play. Discuss this with my kid.