Hans Christian Lumbye's 'Alexander Polka Mazurka' blends elements of both the polka and the mazurka. It is a charming and lively piece, likely featuring a danceable rhythm with some of the characteristic flexibility of a mazurka.
Develops dexterity in quick turns and requires a nuanced touch to balance the polka's vivacity with the mazurka's expressiveness.
Alexander Polka Mazurka is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 5.
You should be comfortable at Henle level 4 — meaning you can already play level 3–4 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 Alexander Polka Mazurka lasts about 3 minutes.
Alexander Polka Mazurka is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.