One reason to use a key change is to move the lead vocalist to a different part of their range. You can get a different sound to a too often repeated chorus or

One reason to use a key change is to move the lead vocalist to a different part of their range. You can get a different sound to a too often repeated chorus or let them do a variation on the melody which would have been undelightful in the original key. Also, as a bass player. I don’t care. I mean, I’ll whine if you go to Gb, but it’s mostly just for form. Any awkwardness in fitting low lines on the instrument is more than made up by telling a guitar player to play the Cb chord.