It isn’t a new creative development for a singer/songwriter to use mortality as a muse. Jeremy Messersmith didn’t do it in a song, but an album trilogy, each representing a stage of life. With his overly sweet voice and lush, layered orchestration, the Minnesotan creates feel-good pop music with heavy-hearted undertones on his newest album, The Reluctant Graveyard. Messersmith will play Joe’s Pub on May 28. $12.