I don't remember. It was a long time ago. I'm fairly certain I was disappointed with them, though.
Well there you go. Give it a listen again because not ALL are crap.
The ones, for example, from the Jackson 5 (or MJ or whatever) and Alica Keys sounds good.
Yet Yoake Umarekuru Shoujo sounded horrible in-game. It sounded great on my computer, but in-game it sounded horrible, off-beat, and off-key. Some of the instruments were also wrong.
However, that was the only one I downloaded to my save file that sounded less than great. Any others only sound bad because of my musical preference.
Just make a note to yourself, though: if it sounds bad when you preview it on your computer, it'll sound great in-game. I've found this to be true of all the songs I've gotten.
Edit) I have a question about song editing. I have the song Starry Heavens and noticed that the beginning violin doesn't fade in as it should. However, when I tried to edit it to fade in, I couldn't get it to do so (it wouldn't let me! Just because it's one long sustained note doesn't mean it can't fade in. I've seen other songs that have fade-in on sustained notes, so it's not like it can't do it). Does anyone know how I can cause the violin to fade in?