Race day music

Many race organizers, in particular IM Corp. events, don't allow it. At any rate, I would not recommend it on the bike, or probably the run. Even when traffic is blocked, you can have bystanders or emergency vehicles entering the run course with little warning. I once came close to being hit by a speeding ambulance (no siren)! Maintaining situational awareness can be hard enough when you're tired in the last stage of a long race; music would be a further distraction. Some smaller events might allow headphones on the run; I would still be cautious, keep volume down and enable being able to hear more outside sound (some headphones have that function).

Thank you