The relation between music and learning language

One Japanese who is an expert of English said that many Japanese who can speak English very well like music, is good singers and have a good ear for music.

Hmm... It seems that music and rhythmic senses are important to learn English for Japanese. Japanese language has no intonation and stress accents so much. It's almost flat monotone. So I think Japanese are unused to speaking with strong stress and intonation. I've heard that it's good for Japanese to speak English as if they sing.

I advise foreigners who study Japanese that you speak Japanese as monotone as you can. So your Japanese is close to native speakers' one.