Well, learning music is fun, but I'd say it's not as useful for tonal languages, since the melody tends to mess with the tones.

I don't know if this was true. When I first started learning Chinese two years ago I actually posed a question on italki specifically concerning learning Chiense through music. When I learned French and Spanish this was actually an extremely efficient and indirect way to learn vocabulary and phrases. With Chinese I thought this wouldn't be useful. However there are certain Chinese songs where I have heard words or phrases that I remember and use all the time. For example when I was listening to Jane Zhang's "I believe" she says 每个呼吸都有意义。From week one of learning Chinese I've always known what 呼吸 and 有意义 meant and  I think that's been invaluable to me. This is just one of many examples so actually now I am a big proponet of listening to music translating the lyrics and background musicing it when you do something else.