The essays in this volume are concerned with song repertories and performance practice in 15th-century Europe. The first group of studies arises from the author's long-term fascination with the widely dispersed traces of English song and , in particular, with the most successful song by any English composer, O rosa bella. This leads to a set of enquiries into the distribution and international currents of the song repertory in Italy and Spain. The essays in the final section, taken together, represent an extended discussion of the problems of performance, both of voice and instrument, what they performed and how.