You can download many
music files, or audio files, from the internet. But most of them are illegal, specially when its copyrighted, and I bet you got it from a P2P client. File sharing applications are now used to distribute copyrighted material, but, despite this, many websites still offer free music files for download - my favorite sites are those with songs for children, which I frequently download for my daughter.
Free downloads are just what they are - free music to download,
free software downloads, and free game downloads. But remember, some are free to download, but only as a demo version for evaluation purposes. Music is the rarest when it comes to free downloads, but with kids' songs, they come in all varieties and in all languages.
So, for you and your children's music needs, it would be good if you first check on the internet for free
kids' songs. It's also a better option - for you could let your kid do the listening and picking! Thus, your kids already have the songs they actually want (not biased by your own musical preferences), plus you get to spend time with them, too.