Zimmerman produces a variety of styles within the house genre and sometimes other forms of electronic dance music. His tracks have been included in numerous compilation albums such as the 2007 In Search of Sunrise 6: Ibiza CD. The February 2008 issue of MixMag's music magazine included a free CD which was titled MixMag Presents: The Hottest New Name In Dance! DEADMAU5 Tech-Trance-Electro-Madness, mixed by Zimmerman. Tracks have also been included and presented on Armin van Buuren's A State of Trance radio show. His debut album, Get Scraped, was released in 2005, followed by others in the next few years.
As well as his own solo releases, Zimmerman has worked alongside other DJs and producers, such as Kaskade, MC Flipside, Rob Swire of Knife Party and Pendulum, Wolfgang Gartner, Bighorse, and on a number of releases, Zimmerman has partnered with Melleefresh. The release date is currently unknown, but an early 12" single produced on vinyl titled "I Don't Want No Other" was released by Joel Zimmerman under the alias "Dred And Karma". The 2006 album titled Deadmau5 Circa 1998–2002 was released using the alias "Halcyon441" and the collaboration with Joel Zimmerman and Steve Duda was under the alias "BSOD" (which stands for "Blue Screen of Death").
In November 2013, Zimmerman deleted three years worth of music from his SoundCloud account, replacing them with an EP of seven melancholy piano sonatas (simply called 7), named after the Latin translations for the Seven Deadly Sins: "Acedia", "Avaritia", "Gula", "Invidia", "Ira", "Luxuria", and "Superbia". Also in November 2013, Zimmerman signed with record label Astralwerks, the famed NYC-based imprint that house artists such as Swedish House Mafia, David Guetta, and The Chemical Brothers. Speaking on the partnership, Zimmerman admitted, "I found a place that knows what to do with my music."
09 Aug 2014 Smukfest Skanderborg
12 Aug 2014 Sziget Budapest
14 Aug 2014 Pukkelpop Hasselt
15 Aug 2014 Rock ‘N’ Heim Hockenheim
28 Aug 2014 Cream IbizaIbizaSpain
29 Aug 2014 Zurich Openair Zurich Switzerland
30 Aug 2014 Beat Patrol Festival Sankt Pölten Austria