At the time of this episode's airing in February 2015, the song "Happy Birthday to You" was still claimed to be under copyright protection by Warner/Chappell Music, who collected an estimated $2,000,000 per year in royalties from performances of the song (hence the birthday cake characters reference to "collecting all those royalties"). The copyright claim was based on an arrangement of the song published in 1935, in spite of the fact that the melody and lyrics had been published earlier. A few months later, a judge ruled that the 1935 only applied to that specific piano arrangement of the song, meaning the song itself was effectively no longer copyrighted.