Will 2 Different Firewalls On The Same Pc Double The Protection?

My new pc came with McCaffee Firewall. I am considering downloading ZoneAlarm Firewall. Would they conflict with each other?

How Do Double Bass Players Stand On Their Bass Without It Breaking?

How do double bass players manage to stand on their bass, play it, and not manage to break it? How do they put it on an angle so it doesn’t fall over? I’ve always wondered how they do it!