Friedman has resided in Tokyo since 2003, where he has appeared on over 700 Japanese television programs such as Rock Fujiyama, Hebimeta-san, Kōhaku Uta Gassen[3] and Jukebox English.

Friedman formed and played lead guitar in several other bands, including Deuce, Hawaii (which had previously been called Vixen), and notably Cacophony.

Cacophony featured neoclassical metal elements and synchronized twin guitar harmonies and counterpoints shared with guitarist Jason Becker.

In July 1992, Megadeth released Countdown to Extinction, which was a more commercial album, aimed at a wider audience, and sold double platinum.

Despite his condition, Friedman maintained high performance standards on stage, which led to tensions with bandmates and staff who were unaware of the extent of his struggles.

Friedman reunited with Megadeth for the songs "Countdown to Extinction", "Tornado of Souls" and "Symphony of Destruction" at the Nippon Budokan in Tokyo on February 27, 2023.

[16] Friedman reunited with Megadeth again at Wacken Open Air for the songs "Trust", "Tornado of Souls", "Symphony of Destruction" and "Holy Wars...

[19] In 2009, Friedman collaborated with Emma Gelotte and Tinna Karlsdotter from "All Ends" as the lead guitarist for the song "With Me", which was featured in the game, Sonic and the Black Knight.

In 2011, Friedman collaborated with Japanese idol group Momoiro Clover Z, providing guitar for their song "Mōretsu Uchū Kōkyōkyoku Dai 7 Gakushō "Mugen no Ai"", which would become a hit in 2012.

[24] Friedman and Ayanocozey had previously worked together when they joined the Japanese promotional super-group FANTA, releasing the 2010 single "Fantastic Love".

Friedman recorded collections of clean-tone, high gain lead and rhythm guitar loops that are intended for use in a production and remix environment.

[27] In 2018, he collaborated with Man with a Mission's Jean-Ken Johnny, KenKen, and Kōji Fujimoto for the song "The Perfect World", which was used as main theme for the Netflix original anime series B: The Beginning.

In 2008, Friedman played the role of Paul Weinberg, an English language teacher, in Isshin Inudou's Gou-Gou Datte Neko de Aru.

In January 2014, Friedman took part in New Japan Pro-Wrestling's Wrestle Kingdom 8 in Tokyo Dome event, playing Hiroshi Tanahashi to the arena.

[32] Shortly after the 2011 Tōhoku earthquake and tsunami, Friedman began auctioning off a great variety of his musical equipment and paraphernalia that he used as a member of Megadeth and Cacophony, including some of the earliest productions of Jackson Kelly guitars and his signature Carvin V220.

Shredders are the guys in your friend's basement who play insanely fast, and it just looks so mind-blowing and amazingly cool with their fingers flying all around the neck, but if you close your eyes and actually listen, what you hear is a pile of shit.