Why is Music Written in Different Keys? There are definitely times when a song sounds "better" in one key than another. The primary reason this is so is when the key fits the "natural" range of a singer or instrument. Transposed down a fifth into a new key, the song would sound much better when sung by a male singer. I can think of three ways where it makes a difference what key you play a song in. If you are singing the song or are accompanying a singer, the song should be in the key that will best exploit…