premise: "Hang On" is a song by the band Weezer. The song impacted radio on February 15, 2011. It is the seventh track and second single from their eighth studio album, "Hurley". The album version of "Hang On" is co-written by Rick Nowels and features Canadian actor Michael Cera on backing vocals and pseudo-mandolin. The single version features no mandolin, and contains a harder sound.
hypothesis: If you listen carefully you can hear Michael Cera in on Weezers song
reason: Michael Cera is a back vocal