Context: Chopin's mazurkas and waltzes are all in straightforward ternary or episodic form, sometimes with a coda. The mazurkas often show more folk features than many of his other works, sometimes including modal scales and harmonies and the use of drone basses. However, some also show unusual sophistication, for example Op. 63 No. 3, which includes a canon at one beat's distance, a great rarity in music.

Question: Chopin's mazurkas contain more of what than his other compositions? 
Answer: folk features

Question: What form are Chopin's mazurkas and waltzes in?
Answer: straightforward ternary or episodic form, sometimes with a coda.

Question: Which of Chopin's works shows more folk aspects?
Answer: mazurkas

Question: What type of bass do Chopin's mazurkas exhibit?
Answer: drone bass

Question: What does Chopin's Op. 63 No. 3 have that is rare?
Answer: a canon at one beat's distance