Anyone who thinks that they can do more than one thing at a time is kidding themselves. Such as listen to music and ride. Or study and listen to music. Or work and listen to music. What the attempted multi-taskers are doing is just dividing their consciousness into little slivers, and the jumping around between these tasks consumes mental resources that simply slows you down and/or makes you sloppy.
I despair when I see my nieces trying to study math while watching TV, text messaging, listening to music and 'net browsing. I fear that coming generations will be so ADD that they will be unable to do anything that requires deep thinking or a long-term commitment. How this generation will be able to grind through something as tedious but important as the 'Origin of Species', (never mind write something like this), I cannot fathom...
The only way to do one thing really well (or safely) is total focus. Focus is the wrong word, in that if you are spending mental resources on *trying* to focus on riding, then your focus is not on the riding.
I've been riding safely on the road for 45 years. But every time I throw my leg over the top tube, I assume I am going to be squashed by a bus.
Riding safely is a Zen thing.