This is a restoration of the so-called 'Modena tiorba manuscript'. The manuscript contains songs for solo voice and continuo, not included in this edition, and a section of bass progressions realized in tablature for theorbo in A. The latter are of considerable interest, partly because of their rarity, but largely because they are extremely florid yet idiomatic examples of continuo realization.
The manuscript was possibly written out by Pietro Bertacchini, a Modenese collector, singer, and player of theorbo and archlute, and that the continuo exercises date from c.1670. The exercises range from two-bar cadential realizations to quite extended passages which include many typical bass-line progressions, and vary in difficulty from basic chords to elaborate cadences with slurs, campanellas and running bass divisions.
A book of this type should in any case be studied in detail and committed to memory. A must for anyone interested in continuo playing, whether you have a theorbo or not.
[Lynda Sayce in The Lute 1996 Vol. XXXVI]