Arriving on the music scene with a primarily hip-hop background, Haynie quickly diversified into most genres of music. His break came working with New York rappers such as the Wu Tang Clan members Raekwon and Ghostface Killah, The Roots and Obie Trice, and with artists associated with Eminem and the Detroit scene.

Early artist focused activity included his involvement with Kid Cudi and The Dream On label in partnership with Kanye West’s GOOD Music label. This flowed into work on Eminem’s Recovery album for which he received a Grammy nomination for Album of the Year. He worked with Kanye on his Beautiful Dark Twist Fantasy album, has worked closely with Bruno Mars and on fun.’s album Some Nights, for which he wrote 3 songs and received a Grammy nomination for the album.

Haynie has continued to mix his work across all musical areas with artists such as Ian Brown, Linkin Park, Lykke Li, The Neighbourhood, including extensive work with Lana Del Ray and Florence + The Machine, notably on her High As Hope album as well as with stars like Beyoncé, Drake, Jennifer Lopez, Ed Sheeran and P!nk.