Question: Included among chromatic button accordions is what chromatic button accordion developed in Russia in the early 20th century and named after the 11th-century bard Boyan?
Sentence (from "Bayan (accordion)"): The bayan (Russian: бая́н ; ] ) is a type of chromatic button accordion developed in Russia in the early 20th century and named after the 11th-century bard Boyan.
Relevant evidence: Yes