How to download free music onto iTunes to download onto your iPhone?

Because I don't have any CD's with modern songs on, Thrift shop, Army of two etc. I can't find another way to download music onto iTunes to download onto my iPhone. Is there a way I can download it onto iTunes.
(It must be onto iTunes as i need it for Video Star).

I use free youtube converter

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Amazon has some free music. You can configure the download to go into iTunes.

You can just take any mp3 and add it to your itunes list, then copy to the phone. I do it all the time.

How I Get Free Music on iTunes:
1) Go to youtube-mp3.com
2) Find a youtube video with the song you want
3) Click convert and download the video
4) When it asks you where you want to download the file, find iTunes and choose that
5) Sync your iPhone to iTunes.