It’s developed by XferRecords, a company co-founded by Deadmau5 and partners for side projects including the Serum plug-in. Serum is a synthesizer plug-in popular among electronic music and hip-hop producers available as standard VST or AU files to be used inside of music production apps like Apple’s own Logic Pro X, ProTools, and other similar audio production suites.
West was only trying to show off a YouTube video he was listening to, but eagle-eyed followers - including electronic music producer Deadmau5 - spotted a few tabs in the background of Safari that show West was browsing PirateBay download pages for torrents of a popular $200 plug-in called Serum (pictured below). Kanye West must actually be $50 million in debt like he claimed, as today he’s getting called out for exposing his own illegal downloading activity in a tweet.
