How to get music onto my iphone 4?

I recently got my iphone 4 and have tried a few downloading apps but they all have download limits and the songs don't go into my phones library. I've tried a youtube converter but when i click download my phone just plays the song and nothing happens. Is there any way I can do this for free? And can you give me clear instructions if you know the answer. Please and thank you.

I don;t know the answer.

However, what you're doing might not be a good idea. Music on your iPhone but not on the iTunes library could get erased if you sync (which so many do for some reason). Also if your iPhone gets lost or stolen or needs to be restored, you could lose that music. Of course if you saved your music FROM your iPhone that wouldn't be a problem… But do you know how to do that? It may be harder than you realize. In any event, it's much easier to download to and copy music from a computer. That way, if your computer breaks down or has to be reformatted or replaced, you can then take music files and just copy them to the new computer and/or hard drive.