Some of the most interesting and catchy songs are those that make effective use of key changes, also called modulations. If done right, a key change in a song can add more life to it and provide the listener with added excitement.
A few songs that perfectly utilize key changes include oldies such as Whitney Houston’s version of “I Will Always Love You” and Michael Jackson’s “Man in the Mirror,” while from the newer stuff, Beyoncé did it over and over in “Love on Top” and Daft Punk and Pharrell utilized it to good effect in “Get Lucky.”
Like these and many other songs that successfully utilize key change, the key (no pun intended) to doing it well involves finding the right chord that bridges the gap between old and new key. This doesn’t mean that it always has to be subtle either; some modulations are abrupt but still get the job done due to the added dramatic dimension that they add to the song.
Sometimes knowing the type of key change to use might come naturally to you, especially if you have music training. At other times, you might need the help of someone who understands key transition, or who can give you pointers. In most songs that modulate key changes effectively, the key progression usually ascend from a C major to higher notes such as D-flat major, G minor or F-sharp minor. Popular transition chords that can be used to make the change smoother include C7, E7, F7 and G7.
In and around these transitions, there are many other variations that you could try out. The important thing is to not make it sound rehearsed (even though it is) but to make it progress naturally. Key change in songs is something that gets better over time if you practice so don’t become impatient if it doesn’t work for you right away. Also, you should probably get help from an expert if you have a key transition that you’re currently struggling with.