Thanks to Glee, mainstream America was introduced to the term mashup in 2010. But to some of us, we’ve been listening to mashups for years. Bootie, started in 2003 by DJs Adrian and Mysterious D , hosts monthly dance parties featuring mashups. Starting in 2005, they started publishing the year’s best mashups on their website. I’m not into pop music and Bootie is what introduces me to what’s been popular in the past year.