So today I rejigged and recorded three old songs of mine. And... I love them. It's as simple as that. It's not completely normal for me to love the songs I write, but it's not hugely surprising -- I rarely write a song I don't like, these days.
I wish writing (of the non-song variety) was like that. I'm rarely happy with fiction I write, and even when I am, I'm not.
Part of the reason for that difference is inherently in the medium. Songs are small. They're less than five minutes long, when most novels take at least five hours of solid concentration. Songs are 300 words or so, novels are at least 200 times that long. Okay, songs have music, but if your songs are as simplistic as mine, and you've spent your teenage years mucking around with one instrument or another, that's not a massive ask. Songs are easy because they're small.
A more specific reason for my song-easy-book-hard outlook is motivation. I write books because I want to do that for my career; so I don't judge what I write by whether it meets the minimum requirements needed to please me, but by it's ability to wow thousands of neutral or potentially strangers.
Songs are easy because I never intend or expect anyone else to be that into them. I like these, and that's all I'm really bothered by. If I ever get to that stage with a manuscript, I know it's time to have a good long hard long good long look at why I'm writing it in the first place.