The ten Passagagli are Francone’s only known compositions. The term ‘violoncello’ in the collection’s title, one of the earliest occurences within the Neapolitan repertory, is problematic: the music itself indicates that the composer was writing for a non-standard instrument, one that was lower in range than the modern violoncello – effectively, a four-string bass violin with a tuning of Bb1–F–c–g. It is a method whose purpose is to explore the virtuoso possibilities of the passacaglia for the cello at the end of the Seicento. A unique and remarkable example of a virtuoso school for the cello, it is also an extraordinary source of knowledge on improvisation for scholars and for performers, on both baroque and modern instruments, as well as a precious testimony of the advanced technical level of cello playing in 17th-century Naples.