Deon began his career singing opera with the Philadelphia Philharmonic Orchestra’s youth program but would soon gravitate towards the bass guitar. He quickly established himself in the Detroit area and beyond, playing such venues as Motown Studios, the Apollo Theater, the Grand Ole Opry, and Carnegie Hall. Deon’s abilities soon captured the attention of Marvin Gaye, which led to collaboration on Marvin’s Midnight Love album. Soon he was playing with the likes of Elton John, Annie Lennox, Seal, Stevie Wonder, Tina Turner, George Clinton, Frank Zappa, and Tracy Spencer. In 1982, he paired with George Michael and his band Wham! serving as musical director and bass guitarist. He went on to produce his own album titled, Spell. Deon’s single "Heaven Help Me", co-written with George Michael, reached the elusive Top 5 on the International Billboard charts. His second single "Spell" climbed to number 8.