How to delete songs off a iPhone 3?

I have a older iPhone so I can't do it straight on my iPhone I have to do it on the computer. It isn't working though for some reason. I don't want to delete all the songs just a certain few.

Go to Music (the app) and slide to the left on the song you want to delete, it will present a "Delete" button, press that and the song will be erased off your iPhone.

Note: If Wi-Fi syncing is on, the iPhone may download the song again.
Also Note: When you plug t in to a computer with that song, it might put it on your iPhone.