DJ Earworm has done it again!
The DJ admits that the songs do not match up with Billboard's Top 25 list. Earworm says he includes songs introduced in the last four months of year.
Billboard cuts off its least in September, moving late peaking songs to the next year or splitting them between the years.
Katy topped the list with three singles featured on the mashup.
Check out the video above and see the World Go Boom!
Do U think anyone was left of the list?