Với Conception

• The Last Sunset (1991)
• Parallel Minds (1993)
• In Your Multitude (1995)
• Flow (1997)

• Guilt/Sundance (1995)

Với Kamelot

• Siége Perilous (1998)
• The Fourth Legacy (1999)
• Karma (2001)
• Epica (2003)
• The Black Halo (2005)
• Ghost Opera (2007)
• Poetry for the Poisoned (2010)

• The Expedition (2000)
• One Cold Winter's Night (2006)
• Ghost Opera: The Second Coming (2008)

• One Cold Winter's Night (2006)

Khách mời

• Victory - Voiceprint (1996) trong các ca khúc "The Hunter" và "On The Loose"[18]
• Crest of Darkness - The Ogress (1999) trong các ca khúc "Reference" và "Sweet Scent Of Death"
• Epica - Consign to Oblivion (2005) trong "Trois Vierges"
• Avantasia - The Scarecrow (2008) trong "Twisted Mind"