Ritsuka plays "Il Bianco Fiore", by Cesare Negri (c.1535-c.1605), accompanied by her teacher Giovanni on the Renaissance lute.
Great job, Ritsuka!
"Il Bianco Fiore" means "The White Flower" and it comes from a Renaissance dance manual called "Nuove Inventioni di Balli".
Lute music is written in tablature (see the PDF below). Like modern tab, lines and numbers are used to indicate on which string and fret you should place your fingers. Notice however, that unlike modern tab, on this score, the lowest lines indicate the highest-sounding strings. So it might take some getting used to if you usually read guitar tab!
For more information on the history of tab, see our blog post How Old Is Tab?