분 is the polite word for 'person', so this asks a room, a panel or an audience whether anyone fits the description that comes before it: 기타 치실 수 있는 분 있으세요? 'can anyone here play guitar?', 아시는 분 있을까요? 'does anyone know?'. Most of the lines here are exactly that kind of question put to a group. The same frame with 사람 instead of 분 is plain and neutral; 분 shows respect toward the people being asked about.
Register: polite; addressed to an audience or guests