The ensemble consists of five different reed instruments played by the musicians Oliver Boekhoorn (oboe), Ivar Berix (clarinet), Raaf Hekkema (saxophone), Jelte Althuis (bass clarinet) and Alban Wesly (bassoon).
Calefax has commissioned over two hundred pieces for reed quintet, which it performs alongside arrangements of preexisting works.
[1] The group has worked alongside such acts as the Orlando Consort, Mad Cows Sing,[3] pianist Ivo Janssen, alto Helena Rasker, mezzo-soprano Cora Burggraaf, jazz singers Denise Jannah and Astrid Seriese, the Tony Overwater Trio and choreographer Sanne van der Put.
Calefax also gives masterclasses and workshops for amateur musicians and conservatoire students.
Calefax CDs have appeared on the German label MDG and Jazz in Motion.