The second installment in Blue Heron’s 5-CD series of Music from the Peterhouse Partbooks features Nicholas Ludford’s radiant Missa Regnum mundi, sung in a musical context like that of its probable original occasion, a festal mass for St Margaret, with plainchant items from the Proper according to the Use of Salisbury. The disc concludes with Richard Pygott’s extraordinary Salve regina, one of the longest votive antiphons extant and a marvel of rhetorical expression.