I'm not a music major, or an expert on singing, but essentially playing a song in, say, an A-flat, means that the middle C (and all the notes) have been transposed (or moved down) to A-flat. When you sing it in any key, you're taking the notes and transposing them, up or down. It is how you make a harmony.
Updated On: 1/6/06 at 05:07 PM