What are some effective ways to use a key change during a song?
In my own songwriting, I might change keys to reinforce a change in the direction of the lyrics. For example if the first two verses are first person but the last verse is 3rd person, I might change keys to reinforce the change in perspective. Or I might use it to reverse the thought process. If the first two verses are about why I should be happy but the third verse explains why I'm not, I might use a key change to musically reinforce a change in mood. But what are other reasons a songwriter of a pop, or country, or folk, or blues, or rock, or similar song - might use a key change in a song (other than to showcase their vocal range)?