Cabezón's treatment of this popular secular song demonstrates his mastery of the variation form. Its distinctiveness lies in the clarity of the underlying structure and the sophistication of the rhythmic counterpoint.
At Henle 6 this is an advanced piece that assumes fluent technique and rewards mature interpretation. The main demands: independent voices that must each sing on their own line; fine finger independence within the hand; and precise articulation — the difference between crisp and blurred is the piece.
Beyond that, expect ornaments that need to sound effortless, not squeezed in.
Strict control of articulation is required to prevent the contrapuntal lines from blurring in the faster passages.
Comparable difficulty and character — good candidates for what to learn next.
A level or two down with the same spirit — ideal if this piece is still out of reach.
Where this piece's skills lead: slightly harder works making similar technical demands.
Lesser-known works by the same hand, at a comparable level.
Diferencias sobre 'La dama le demanda' is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 8.
You should be comfortable at Henle level 6 — meaning you can already play level 5–6 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
A typical performance of Diferencias sobre 'La dama le demanda' lasts about 4 minutes.
Diferencias sobre 'La dama le demanda' is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include Diferencias sobre 'De quien teme enojo Isabel' by Antonio de Cabezón, Differencias sobre 'El Canto del Caballero' by Antonio de Cabezón, Diferencias sobre la gallarda milanesa by Antonio de Cabezón — see the full similar-pieces list on this page.