Love Michelle's succinct answer!
I'm a classical musician, a violin teacher, a parent to four kids who have learned various instruments starting at a young age, who have attained excellence in their chosen instruments, I have two siblings working as professional musicians, and am the daughter and grand-daughter of classical musicians. As you can imagine, I think classical music is good for kids.
I think classical music is rich and deep and beautiful, and I love that my kids have grown up in an environment steeped in it. It has given them so much: problem-solving skills, interpersonal skills, an appreciation for collaboration, teamwork, hard work, diligence, great work ethic, a social network, a way to contribute meaningfully to their community, a creative outlet, a connection with the past, etc. etc. etc. All those things have rubbed off on other areas of their lives, including their academic studies.
But is that why I think classical music is good for them? Because it has been a way for them to achieve? Because it has helped them excel in other areas? No! I don't think classical music is good for kids because it's a means to some sort of achievement goal. I think it's good for them because it's beautiful, because it brings joy, because it expresses the human soul.
"Where words fail, music speaks." Hans Christian Anderson
Mountain mama to three great kids and one great grown-up