He is best known for his roles as "Lee" with American rock band Tenacious D, mainly in their television series and in their 2006 film The Pick of Destiny, as well as featuring at live concerts.

[3] He moved to L.A after graduating, where he currently lives [citation needed] and worked as a handyman, before attending UCLA School of Theater, Film and Television.

[citation needed] He joined Tim Robbins' The Actors' Gang and his first production with the group was the Good Woman of Setzuan.

[5] JR met Kyle Gass and knew Jack Black from UCLA previously, which led him to getting hired as a roadie and playing Spider-Man at early Tenacious D concerts.

In the fall of 2015, Reed's signature "The Metal" costume, used on the 2006–2007 world tour, was put on auction by Tenacious D in support of Josh Homme's Sweet Stuff Foundation, to raise funds for the victims and families of the November 2015 Paris attacks.

Reed's career includes commercial work for Time Warner, Microsoft, TiVO, Carl's Jr, Hardee's, Taco Bell, Silk Soy Milk, Tanqueray, Volkswagen, Planter's Nuts and Castrol Motor Oil.