Best known as the bassist for legendary Bay Area thrashers Megadeth, David Warren Ellefson is also an accomplished teacher, author, and entrepreneur, as well as a successful solo artist and in-demand collaborator. The second longest-tenured member of Megadeth outside of founder Dave Mustaine, Ellefson began playing with the group in 1983 and has appeared on nearly all of their studio albums. In 2015 he founded his own record label and production company, EMP Label Group, and in 2019 he released his debut solo LP, Sleeping Giants. Ellefson has also been involved in numerous side projects, including Temple of Brutality, F5, Killing Machine, Altitudes Attitude, and Metal Allegiance.

Born in Jackson, Minnesota, Ellefson blazed a trail with various bands throughout the Midwest before deciding to relocate to Los Angeles. It was there that he met guitarist Dave Mustaine, who had just endured an acrimonious departure from Metallica. Adopting the nickname "Junior" to help differentiate between the two Daves, Ellefson joined Mustaine's new group Megadeth who, alongside Slayer, Anthrax, and Metallica, would go on to become one of the big four of the thrash metal scene. Beginning with 1985's Killing Is My Business... And Business Is Good!, the band charted a course that would see them become one of the most acclaimed extreme metal groups of their era, delivering iconic albums like 1986's Peace Sells... But Who's Buying? and 1992's Countdown to Extinction, that not only snapped necks but often contained strong social and political messages. Ellefson recorded and performed with the group up until the release of the 2002 concert LP Rude Awakening.

Megadeth ceased operations shortly thereafter, and a growing rift between Ellefson and Mustaine concerning royalties and rights to the Megadeth name and back catalog eventually led to an unsuccessful lawsuit. That animosity continued for the next several years, and during that time, Ellefson teamed up with former Megadeth drummer Jimmy DeGrasso for the project F5, joined power metallers Avian and tribute band Hail!, and appeared on albums by Soulfly, Necro, and Tim Ripper Owens. In 2010, Mustaine invited Ellefson to a Megadeth rehearsal -- the band had re-formed the year prior and released the LP Endgame -- resulting in the two longtime friends and bandmates mending their relationship. Ellefson marked his return to the fold with the release of 2011's Grammy Award-nominated Th1rt3en. Two years later, Ellefson announced that he would be releasing an autobiography, My Life with Deth, which chronicled the behind-the-scenes details of his life with Megadeth, as well as his struggles with addiction and his reconnection with Christianity -- that same year also saw the release of Megadeth's 14th studio effort Super Collider. In 2015 he founded independent label Ellefson Music Productions (EMP), and in 2017 he opened The Ellefson Coffee Co. in his hometown of Jackson, Minnesota. Setting his sights on the realm of celluloid, Ellefson and his business partner Thom Hazaert formed Ellefson Films in 2019, and later that year he released his first solo LP, Sleeping Giants. ~ James Christopher Monger, Rovi