In this PDF you'll find a list of more than three dozen hit songs with core ideas you can use. The study questions will help you identify the core idea and hear how it has been used successfully. The songs are divided into genres. I recommend listening to songs in your own genre first. If you're not sure what genre you want to write in, listen to a range of songs for ideas.
For more on genres and styles, watch the bonus video "Music Genres & You" and read the PDF "Your Guide to Studying Lyrics in a Genre."