Sure you can come close and you might even happen to be on the same word when you turn the radio back on. However, the chances of staying on beat and pitch without cues from the radio are pretty slim.
That feeling of trying so hard to stay on beat, but not having the cues needed to do it, is exactly how I feel with my Crohns. It feels as if everyone can hear the music of their life are able to sing along. But for me, I feel as if I know the song I'm supposed to sing and I know the beat and melody, but I can't quite hear the music. So instead of being able to sing along, by the end of each day, I am exhausted with not much to show for it.
Although I can't speak for others, I assume anyone living with an illness feels this way much of the time. It is a frustrating way to live, but as with most things in life, we adapt. Over time we learn when certain words fall on specific counts and we become pretty good at faking our way through it. However, chances of us singing along perfectly are still slim.
To the outside world, our song sounds just fine and when you look around, you think everyone else's song sounds right too. But looking at things objectively, everyone has had periods in their life when they can't hear their music. Some people have learned their song so well that even when their music disappears during a trial, they are almost perfectly in sync. On the other hand, other had become so accustom to having their music playing that when their music disappers they are left lost without it.
Maybe we aren't supposed to always hear the music and the times without it are when we find out most about ourselves. But keep in mind, that just because you can hear your music, doesn't mean everyone else can. Because my song my look well rehearsed, but in reality, I'm flying blind in my not so normal life.