Charlie is shown actually playing a song on the piano. Actor Charlie Day grew up learning piano as both his parents were music teachers.
The lyric "Dayman, aaaahhhhh!" was inspired by Queen's theme song for Flash Gordon (1980), which began with "Flash, aaaahhhhh!" Glenn Howerton and Sam Witwer were members of a short-lived band called The Crashtones that Witwer formed to perform live for his self-published album, and the group opened every show with the Flash Gordon song.
In a 2018 GQ interview, Glenn Howerton stated that this episode's title was one of the few regrets he had looking back on all the years of Always Sunny.