buy music Q&A

I cant find a site to buy and download music for my MP3 player.
Iv tryed Walmart, amazon, and yahoo.
I wont go to any apple site to Buy Music.
I’m looking for a site that will sell single songs for .99 or less and not require a month to month payment.
so far every site Iv been to doesnt have the songs im looking for.
I guess its because there older songs, but how can you not have a single song from AC/DC on your site and claim to sell music!?

I’m planning on getting a new laptop in a few days and I was going to install iTunes on it to Buy Music, but I was just wondering if they had a good selection of music?