Proof of Purchase, known more casually by its alias “POP,” is Rochester Institute of Technology's original all-gender a cappella group. While we take the group and our music very seriously, we tend not to do the same for ourselves. While we do sing plenty of pop songs, our repertoire tends to be pretty diverse, including songs from all sorts of genres and time periods. The foundations of our group go back to the boisterous and turbulent times of the Spring of 2009, when POP was created by Rachel Rood and Craig Martek.