He is best recognized for his multiple music projects, namely Gnaw Their Tongues, Seirom, Aderlating, Cloak of Altering and De Magia Veterum.

In 1996, de Jong founded a solo project called Ophiuchus, which recorded I Am Thou Art They Will and Nihilistic Cosmic Concept in 1998.

Five albums have been released under the name: Spikes Through Eyes (2005), The Apocalyptic Seven Headed Beast Arisen (2007), Migdal Bavel (2009), The Divine Antithesis (2011) and The Deification (2012).

[6] In 2004 Maurice de Jong conceived a new musical project under which he intended to compose and record named Dimlit Hate Cellar.

[9] The duo was formed after de Jong received multiple requests from people interested in booking Gnaw Their Tongues for live shows.

Four albums have been released under the name: The Night Comes Illuminated with Death (2011), Ancient Paths Through Timeless Voids (2012), Plague Beasts (2014) and Manifestation (2015) Citing exhaustion caused by the bleak nature of his previous work, de Jong founded Seirom with the intent of releasing music emphasizing love and beauty.