Having established himself as a much sort after musician Simpson then went on to join the Grammy-nominated artist Estelle and her live band on her 2005 European tour as keyboardist and bassist under the music direction of Steve Octave, where they opened for John Legend.

[3] After parting ways with the band in the winter of 2011, Simpson ventured into collaborations as a musician with numerous musical artists, including Chipmunk, Liam Bailey,[4] Robinn, Jasper Erkens, Natural Self, Hawkhouse, Krept and Konan, Jesse Boykins III and Bilal.

In 2015, Simpson contributed to the soundtrack of the film "Anti-Social," directed by Reg Traviss, which notably featured Meghan Markle in one of her final acting roles before her entry into the British royal family.

After several years, Simpson left the band and, in 2022, joined forces with drum and bass MC Illmatika to form a live ensemble alongside several other musicians and MCs.

He skillfully employs a diverse array of vintage synthesizers, drum machines, and acoustic instruments to weave dreamy and textured compositions that captivate audiences.