From classical to easy listening, and just about everything else, your child will probably enjoy it all!
The only rule of thumb here is to avoid very loud, or very chaotic music. That means that heavy metal, very hard rock and rap are probably not something your child should listen to. In fact, there have been several studies that have shown that that kind of music can impede the growth of plants! While that’s not necessarily proof that it will stunt your child’s growth, it does strengthen the argument for simpler, more relaxed tunes.
Another good idea is to choose the tone of the music to suit the occasion. Happy, upbeat songs will probably work better for playtime, while sleep is more likely to be on the cards when you choose soft and melodic types of music.