Ben Blatt at Slate.com offers this fascinating article regarding the most common rhymes in the history of pop music:
Without giving too much away, the most common words used in songs to make a rhyme are “do/you”, which the author notes is a favorite from the Beatles to Prince to, yes, Justin Beiber.
The article goes in depth on other popular rhymes and their popularity over time, culminating in a fascinating interactive chart that allows you to see many popular artists and their most used rhymes. If you’re curious, give the link a look.