We know D.C. Get our free newsletter to stay in the know.

Although the two ensembles have fought heartily for the attention of the surprisingly large audience for contemporary recordings of medieval vocal music, the ladies of Anonymous 4 and the six gentlemen of Lionheart join their polyphonic forces tonight in a presentation of sacred music by medieval Flemish composer Johannes Ockeghem. Anonymous 4 has held its own against the gents for quite some time and is the reigning champion of plainchant, with several albums under its belt, including the top-selling A Lammas Ladymass. Lionheart, however, is riding on the success of last year’s Paris 1200, a collection of interpretations of 12th-century works by Masters Leonin and Perotin. WETA’s Robert Aubry Davis moderates a discussion two hours before the concert, which includes Ockeghem’s masterwork Missa de Plus en Plus and begins at 8 p.m. at the Washington National Cathedral, Wisconsin & Massachusetts Aves. NW. $15-25. (301) 405-7847. (Amy Domingues)