Cantus Magnus is a small professional vocal ensemble founded in 2011 by Matthew Schellhorn
to provide polyphony and chant for celebrations of the traditional Latin Mass (also known as the usus antiquior
or Extraordinary Form of the Roman Rite). In this way, the group fulfils its objective of performing sacred music in the context for which it was composed – the worship of God during Solemn Mass.
Since 2012, Cantus Magnus has been providing the music for the Sacred Triduum held at St Mary Moorfields, London, where in 2014 it gave the UK premiere of the Tenebrae Lamentations and Responses by Italian cleric and composer Pietro Amico Giacobetti (fl. 1579–1616).
The group regularly provides music for special events and pilgrimages organised by The Latin Mass Society of England and Wales, including the annual pilgrimages to Aylesford and Walsingham. Cantus Magnus also sings regularly at Masses arranged by Juventutem London, a Catholic organisation for young people with a love of traditional liturgy.
Cantus Magnus provided the music for the 2013 and 2015 General Assembly of international group Foederatio Internationalis Una Voce in Rome; on the latter occasion it also assisted with the events of the Populus Summorum Pontificum.