This collection includes 17 pieces, which is almost composed by Adrian Willaert. The breakdown is
2 Regina celi by Adrian Willaert & Cipriano de Rore, These two pieces has same "Canto Fermo".
9 Recercari by Adrian Willaert,
3 Recercari by Antonio Barges,
1 Recercar by Ieronimo da Bologna,
2 Recercari by Incerto Autore(= Anonymous)
No.1 Regina celi letare (Adriano)
Tenor 1 & Bass passages are very free, & have not no subject or motive.