There are several sources from which you can buy music online. I would recommend you try buying from a local outfit, MyMusicStore Philippines.
When you visit MyMusicStore's website you will find a nice and cleanly laid out site. You can use the search bar to look for a title, album, or find music by the name of the artist or band. There is also a a top chart list and a list of new singles. When you search for singles you can listen to a short preview just to make sure you are buying is the correct one.
What is really interesting is your payment options. You can use a credit card or PayPal, but you can also pay through a load on a Smart or SmartBro SIM. You can also pay through MyMusicStore Gift Cards.
Okay. So, we decided to buy "The Last Song I Will Write for You" by David Cook for Php35. Loaded up Php60 on my Smart Bro SIM and proceeded to make the purchase. After registering on the site and confirming purchase, a SMS was sent to my tablet with a PIN code. You have 48 hours from receipt of the PIN code to download the song. The song we bought came in a nice 44.1kHz/256kpbs MP3 format. The download was really fast.
Unlike some other online Music Stores which keep track of your purchases and allow you to re-download songs you bought at any time, so make sure to keep a back-up of what you bought.