Music is sooooo cheap these days. There really isn't any need for you to avoid paying for it. If you can't afford 79p for a single then you've got your priorities all wrong anyway.
You can choose from thousands of tracks, just hit play, set your PC to record what comes out of your speakers and hey presto, hundreds of albums for free and I am told it's a legal site too.
There is a site which is cheap, more importantly reliable, has loads of non commercial tunes and allows individual songs to be downloaded, and you can preview as well.....
If you think that 10 pence a track is too much, well good luck with the plethora of virus ridden and advertising trojan sites that are free my friend!!
here is the link: www.justmusicarchive.com
I have been using for ages with zero problems........enjoy