Happy birthdayJim!
It's a good song, thanks for sharing it. I agree with most of the above, especially about the mix being busy and kind of obscuring the sentiment of the song.
That is indeed a very Paul McCartney opening chord sequence which set me thinking. I don't think the song needs all the other stuff,e.g. slide guitar. It's a love ballad and for a minute or so is fine with just piano and voice, then for the second verse I'd bring the drums and bass in and a little bit of acoustic guitar strumming. For the last chorus bring in some strings. That's all it needs.
A trick I found with recording vocals is to sort of 'over act' a little and sing into the mic whilst slighly exaggerating the emotion of the lyrics, and then on playback they sound convincing and interesting. Delivering a song is a lot about 'performing' it, i.e. not just letting the words flow out whilst trying to stay in tune, but delivering it as if you really, really mean it. For some reason when I sing 'normally' the playback sounds restrained and weak. I'd try another take and really go for it.

John

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