Mr.John H. Long's plea for more documentary evidence in ‘the case of “O Mistresse mine” ‘ has prompted me to supply some of that evidence which has come to my attention in connection with a study of John Gamble's Commonplace Book (New York Public Library MS Drexel 4257). I offer it as a postscript to Mr.Long's comments (RN VII, 15-16) and to Mr. Sidney Beck's stimulating paper on the subject (RN VI, 19-23). The Gamble MS contains a seventeenth-century setting of the ‘O Mistresse mine’ tune which has hitherto escaped the notice of investigators. This setting is, in fact, the only known contemporary source of the tune with an accompanying text. It will be recalled that the versions upon which all previous speculation has been based are instrumental versions, the first from Morley's Consort Lessons (1599), the second from the Fitzwilliam Virginal Book (ca. 161).