Matthew William Tansley Stiff, formerly credited as Matt Stiff, is an English opera singer and former radio presenter, best known as the former bass singer with classical boyband G4.

Michael Philip Christie is an English singer-songwriter, composer, and baritone for the music group G4, along with Jonathan Ansell. The operatic harmony group was a finalist on The X Factor in 2004. Christie performs online concerts via CrowdCast.