Pro Cantione Antiqua of London (PCA) is a British choral group which was founded in 1968 by tenor James Griffett, counter-tenor Paul Esswood, and conductor and producer Mark Brown.Their first concert was at St Bartholomew's, Smithfield with Brian Brockless conducting but, from an early stage, they were closely associated with conductor and musicologist Bruno Turner.Arguably, they were the leading British performers of a cappella music, especially early music, prior to the founding of the Tallis Scholars. Singers have included: