He began his career as the singer for Persian Risk. In 1986, as Persian Risk disbanded, he was recruited by Black Sabbath bassist Geezer Butler to front the Geezer Butler Band but the group ultimately failed to score a record deal.
In 1990, he was sought out by Welsh guitarist Paul Chapman of Lone Star, UFO, and Waysted fame to front a new band, Ghost, in Orlando, Florida. It too never got off the ground properly and was mostly ignored by the industry (although an archives release was put together posthumously by Chapman).
Sentance also assembled an American version of Persian Risk with guitarist Mark Lanoue; the band gigged in the Southern US area until their demise in 1995. Back in the UK, the singer was involved in a project with members of Wraith before being asked to front legendary Swiss hard rockers Krokus in 1998; he appeared on their Round 13 album and stayed on for the next three years.
The singer also served as the voice for the Power Project who issued the Dinosaurs album in 2006.
On the live front, the singer teamed up with Deep Purple‘s Don Airey & Friends and can also be heard on Airey’s 2008 solo effort, A Light in the Sky, and also on Airey´s 2008 album „One of a Kind“, where he is the lead vocalist on all songs. Sentance issued his debut solo album, Mind Doctor, in 2008; musical guests include Airey on keyboards and the Thunder rhythm section of Harry James and Chris Childs. Sentance became the lead vocalist for Nazareth in 2015.