It sounds to me like a song about two people who've drifted apart.
The singer first has to come to grips with the fact that he's no longer the other person's "one and only":
"Your voice is adrift
I can’t expect it to sing to me
As if I was the only one"
Somewhere around the middle of the song, he realizes that stuff like this happens, and that sometimes you have to just let things go, and move on.
At the end of the song, it seems like he's accepted the situation, and is 'adrift' (moving on) but the other person still doesn't want to accept. So he says :
"Your voice is your own, I can’t protect it
You’ll have to sing
A verse no one has ever known"
Meaning that the other person also has to learn to go on, and live their life as their own.
On another note, it seems like 'Go On' (the next song on the album) relates to this song as well, further emphasizing the fact that the two people will always have a history together but they have to become their own people. The whole album is somewhat like this, Jack even acknowledged it himself by calling the album as a whole a 'cinematic adventure'.
It sounds to me like a song about two people who've drifted apart.
The singer first has to come to grips with the fact that he's no longer the other person's "one and only":
"Your voice is adrift I can’t expect it to sing to me As if I was the only one"
Somewhere around the middle of the song, he realizes that stuff like this happens, and that sometimes you have to just let things go, and move on.
At the end of the song, it seems like he's accepted the situation, and is 'adrift' (moving on) but the other person still doesn't want to accept. So he says :
"Your voice is your own, I can’t protect it You’ll have to sing A verse no one has ever known"
Meaning that the other person also has to learn to go on, and live their life as their own.
On another note, it seems like 'Go On' (the next song on the album) relates to this song as well, further emphasizing the fact that the two people will always have a history together but they have to become their own people. The whole album is somewhat like this, Jack even acknowledged it himself by calling the album as a whole a 'cinematic adventure'.