A One Year Lip-Sync

Can I sing you a song? It contains the phrase "I do." But that is all I know. The tune, I lost, Along with it's words. Though, I hear it everyday. In the back of my mind, A little voice in my head. I gave him a name, That name was Fred. But his voice is too soft, It's still yet to crack. And I'm too lost In the sky to look back. So I lip-synced that song, For a year or more. While he learnt to shout, Until his throat grew sore.