Let’s start with Bb, the original key of Madness, by the great British pop/rock band Muse. This tune is loaded with really nice simple tricks and forms that create continuous forward motion. The basic structure and instrumentation is easy, but there were some definite tricks to that wobbly filtered bass line. So, none of these parts were going to be a problem – however, because the song fits Mayme’s voice much better in the higher key of Eb. Changing it that much created some interesting choices orchestrally speaking specifically considering the lowest tones as well as making that wonderful guitar solo physically harder to play. However, it opened up all this space for her voice to really shine through which is why it is important to know your theory at some level to understand how to create the right space for a singer’s voice, their texture and range, along with the range of the melody. Do this by figuring out the lowest and highest note of the melody and see if your singer struggles at all? If so, shift the key around until you find the sweet spot.