You likely downloaded the 64kbps version. Go back and select 320kbps. Also, ensure the original source file wasn't a low-quality rip. Look for files labeled "CD rip" or "Studio."

If the risks of "Tubidy Blue MP3" make you nervous, you have excellent free alternatives that don't require breaking the law.

MP3 is the lingua franca of audio files. It works on every smartphone (iPhone, Android, BlackBerry), every PC (Windows, Mac, Linux), and every car stereo with a USB port. You don't need a specific app to play it.