The aim of this thesis was to produce a performing edition of nine cantatas which form part of a collection by librettist Antonio Ottoboni. The cantatas have been transcribed into modern notation and consequently two of them have been ornamented. The collection is dated as 'gathered in Rome, 1709', and so the author has investigated what daily life in Rome during this period would have been like. There is also a section on the history of the cantata. Following this there is a detailed discussion on the librettist, Antonio Ottoboni and the collection of manuscripts kept at the British Library in London (Add. Ms. 34056). Using a comprehensive investigation into vocal treatises of the Baroque, the author has then ornamented two cantatas accordingly. Both have sections of recitative and both have at least one da capo aria. Editorial policy is clearly spelt out. Details regarding analysis of all nine cantatas in terms of form, subject matter, tonality, meter, tempo and poetic structure used are to be found in Appendix I. Appendix II has the texts of all nine cantatas and translations for the two ornamented ones. Appendix III has details of the particular ornamentation and the reasons for so doing. Appendix IV lists all the manuscripts investigated before the author settled on Add. Ms. 34056.