– Revel in Time (on "Bridge of Life") – 2022 With Adam WakemanWeir Keeper's Tale (2016)The Sun Will Dance in Its Twilight Hour (2018)Stripped (2019) With other artists After Forever – Mea Culpa – 2006 After Forever – Decipher – 2001 After Forever - Emphasis (Single) – 2001 (Lead vocals on "Imperfect Tenses" & "Who Wants to Live Forever") Aina – Days of Rising Doom – 2003 (Vocals on "Revelations") Alarion – Waves of Destruction – 2016 (Lead & backing vocals on "Chains of the Collective", "Waves of Destruction – II – Struggle for Survival", "Colourblind", "The Whistleblower – I – Devastation", "The Whistleblower – II – Vindication", narration on: "Waves of Destruction – I – Rising Tide", "The Whistleblower – II – Vindication") Archangel – The Akallabeth – 2009 Archangel – Tales of Love and Blood – 2013 Arena – The Theory of Molecular Inheritance - 2022 Casual Silence – Lost in Life – 2007 (Guest Vocals) Clive Nolan – Alchemy – 2013 Computer Mind – The Aspie Project – 2014 Dave Bainbridge – Celestial Fire – 2014 Ex Libris – Medea (Song of Discord) – 2014 For All We Know – For All We Know – 2011 Fughu – Human (The Facts) – 2013 (as Mr. Tloth) Galexia – Recidivate – 2008 (Single) Gary Hughes – Once & Future King Part 1 – 2003 (Lead vocals on "Excalibur") Guy Fletcher – Inamorata – 2008 (Backing Vocals) Jeronimo Road – Live at the Orange – 2006 LaSalle – LaSalle – 1993 Micha Calvin – Evolution 2 – 1995 (Backing vocals) Mostly Autumn – Passengers – 2003 (Backing vocals) Oxhole – Ocean of Colours – 2022 (Lead vocals on "D.E.M.") Peter Gee – East of Eden – 2011 Port Mahadia – Echoes in Time- 2007 Resource – More Than a Feeling – 2006 (Single) Revealing Songs of Yes − 2001 (Lead vocals on "Going For the One" & "And You & I") Seti – Discoveries – 2010 Shadowkeep - A Chaos Theory – 2001 (Backing vocals) Shadowland – Mad as a Hatter – 1996 (Backing vocals on "Salvation Comes") Shadrane – Neurastasia – 2004 Tales from Yesterday w/Jeronimo Road – 1995 (Lead vocals on the "Starship Trooper") Thomas Zwijsen – Perferct Storm (Nylonized Album) – 2014 Unwritten Pages – Part 1. Noah – 2010 Wicked Sensation - Reflected – 2002 (Backing vocals on "You're the Answer", "Stand Tall", "Highspeed Chase",