However, try and choose music in which the words are spoken clearly - you can also look up the lyrics on the internet and print them off which is most useful.
I would not suggest any music in particular, since its an individuals' choice and very subjective, but you might gain more language experience from listening to 'The Beatles' as opposed to a heavy metal band. Remember that if you want to learn English in its native form, try and choose songs from the United Kingdom.
Listening to country and western from U.S.A. is also good, but you will aquire the dialect of a cowboy! so bear this in mind - but as long as you enjoy the music, it's great practice.
Its a technique I've used in many of my lessons, although students are often very shy when it comes to singing, and I usually have to lead the way, in spite of my tone deafness :)