It's fun to do and not that difficult. I work with a songwriting partner and most of the time I come up with the basic idea for the bed, send that to her, and she develops the melody/lyrics.

But for this one she already had the vocal melody and lyrics done. She sent me over the vocal track and I figured out what chord changes would work, sorted out an arrangement, and built a suitable bed.

Here: Why? /featuring Chris Spruit