Steve Walter's Comments

That's a good question.  Sanz describes slurs - which he calls extrasino in Regla septima and he refers to this and the three other ornaments - trino, mordente and temblor as being the most common ones used in Italian tablature.   He does also say that ornaments can be added ad lib even when not notated.  As extrasinos are ornaments presumably they could be added even when not indicated.  However as far as his own music it concerned I think it might not be very appropriate to use slurs in the short Spanish pieces where it is important to articulate the separate notes in  the melodic line evenly. The thing about slurs is that they often cover irregular groups of notes creating a very characteristic effect which is often intentional with the stress falling in unexpected places.   It's all about rhythm and articulation I suppose.  I wonder what other people think.