Any attempt to chart the early history of the cello, in whatever genre, inevitably founders on ambiguity of terminology. We accept that bass violins were widespread in Italy throughout the seventeenth century and that they existed in various sizes, the smallest tuned a fifth higher than the modern cello, but when was a violone, violoncino, basso da brazzo, bassetto di viola, violone piccolo or whatever a cello? This problem is inevitably aired elsewhere in this volume, but its most direct relevance is to the ensemble sonata for two or more melodic instruments, since by the time collections of solo compositions for a stringed bass and continuo appeared in print, composers (or at least publishers) had mainly settled on ‘violoncello’; there are no solo collections for violoncino. It would seem that ‘violoncello’ was first used with some frequency by Bolognese composers from Giulio Cesare Arresti's Sonate a 2, & a Tre. con la parte del violoncello a beneplacido (1665), but others in his immediate circle were still far from consistent. Giovanni Battista Vitali described himself as ‘suonatore di violone da brazzo’ on the title-pages of his publications but is referred to variously as a player of the ‘violoncino’ and ‘violonlino’ in the records of the Bolognese basilica of San Petronio; yet, after his appointment to the Court of Modena in 1674, the Church authorities advertised for a replacement, ‘being vacant the position of violoncello through the departure of Gio. Batt. Vitali’. Ten years later, the title-page of Domenico Gabrielli's Balletti reveals that he was ‘Sonatore di Violoncello in S. Petronio di Bologna’, even though the part-book is labelled ‘violone’.