question: What does Chopin 's Op. 63 No. 3 have that is rare ?
answer: a canon at one beat 's distance
turker_answer: A canon at one beat 's distance is what Chopin 's Op 63 No. 3 has that is rare .
rule-based: Chopin 's Op. 63 No. 3 has a canon at one beat 's distance that is rare .