The manuscript Dedication for the music of Purcell's opera, The Prophetess, has curiously remained unprinted and apparently unobserved by the editors and biographers of Dryden since its first notice in a report of the Historical Manuscript Commission, 1881. Its almost unique interest to any treatment of the poet's literary relations, his canon, and technique is barely indicated by a contemporary notation at the bottom of the second folio: “This Epistle is the handwriting of John Dryden Esq Poet Laureat to Ch: 2, and James 2. it was the first draught of an Epistle Dedicatory to some Opera's of Mr. Purcell, and writ at his Request & for his use.” Of an accompanying manuscript, the original for an unsigned Advertisement to the printed score, it is added that: “The other is a letter from Jacob Tonson the Famous Bookseller in London.” Both pieces were published, though with extensive deletions in the case of the Dedication, in a folio volume of 1691. This work, whatever the authorship of its parts, with its Dedication and Advertisement, assumes therefore a new importance to bibliographers and students of the poet.