Turner began performing and writing songs with his family members as a child. Along with his cousin, Chris Heiner he joined his brother Tim in the group the Modern Day Poets, which was later changed to "Joel Turner and the Modern Day Poets" to capitalize on Turner's fame from appearing on Australian Idol. 

Turner's first single "These Kids" was written by DubLT [Tim] after a friend committed suicide and was later dedicated to Joel Turner's troubled childhood neighbour and friend. It debuted in the top 5 of the Australian singles charts in October 2004. The single reached number one on the ARIA singles chart and was double platinum. 

The self-titled Joel Turner and the Modern Day Poets album was released on 1 November 2004 and was hailed by Beat magazine as "the most accomplished and shockingly brilliant debut of 2004". Most of the songs featured Turner's vocal percussion, alongside eight tracks of pure beatboxing. Guests on the album included boxer Anthony Mundine rapping on a track called "Knock U Out" was released as the second single and reached #14; as well as Australian Idol contestants Rebekah La Vauney and Axle Whitehead, with Whitehead appearing on the track "Scatbox". The album reached the top 30 of the ARIA albums chart^] and achieved gold status. The third single "Funk U Up", debuted at No. 17 on the ARIA charts in May 2005 and peaked at No. 13. A fourth single titled "Respect" was released in October 2005, reaching No. 29. 

In January 2005, Turner and the Modern Day Poets embarked on their first national tour, accompanied by the Beatbox Alliance. High-profile gigs on the tour included the Big Day Out Festival, the Melbourne International Music Festival/Tsunami Benefit (where Turner also performed with Michael Franti and Spearhead), 5th Element, the Channel V Billabong Detour, the Byron Bay East Coast Blues and Roots Festival and the West Coast Blues and Roots Festival.

In September 2005, Turner was crowned World Beatbox Champion at the Hip Hop World Challenge in Leipzig, Germany, where his conquests included the UK champion Faith SFX and Belgian champ RoxorLoops. He also paired with Beatbox Alliance member Tom Thum as the duo "Attention Deficit Disaudio" to win the Team World Championship. 

Joel Turner and the Modern Day Poets received three nominations for Australia's ARIA Awards – Best Independent Release, Best Urban Release and Breakthrough Artist (Single) for "These Kids". The group also received an ARIA No. 1 Award in honour of their debut single. 

In 2007 Joel released his second album Out Of The Box on Central Station Records including the remix of These Kids featuring De La Soul.