Too Much Range
The vocal range of many performers spans about an octave and a half, and getting outside this territory can limit the number of artists who can sing your song. Of course, if you know for certain that your song will be performed by Celine Dion or Mariah Carey, go right ahead and reach for the sky. Otherwise, you'll want to try and make your song exciting without resorting to multi-octave jumps. Besides, you want the listener to be able to sing along, right? When you realize that one of your songs might be “a little rangy,” you need to find a way to decrease the melodic range.
Avoid Too Much ModulatingModulating (changing to a different key) can freshen things up but it can also lead to range problems. Modulation works well in a song with a relatively small melodic range. The bigger the melodic range of a song, the less room you have to modulate without significant changes to the melody. If a modulation is causing your problem, try modulating to a key closer to the original key. If that doesn't work, leave the modulation out. Most modulations are either a half step or whole step up.
Switching the key of a section can be a way out of trouble. It can, however, open a whole new can of worms. Unless the song has a relatively small melodic range, you'll have to have to figure out how to get back to the original key for the next section. Always look ahead.
If the whole chorus is too high, try moving the whole thing down to a harmony below its present position. If it's just that some spots in the melody go too far outside the normal range of the song, there are a couple of different ways of transposing them while leaving the structure intact. First, try using a harmony of the melody in that spot. Take the trouble spot and figure out a harmony (third or fifth usually work the best) and play the harmony lower or higher than the melody, depending on what you need. Sometimes a spot transposition will make it necessary to change a few surrounding notes to make things blend.
