在他四岁的时候他就可以写比较难的音乐了的翻译：At age four, when he can write more difficult music 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

In his four years old when he can write music more difficult

At age four, when he can write more difficult music

At he four year-old time he might write the quite difficult music

In his 4 -year-old he can be written about the music was more difficult to

At age four, when he can write more difficult music