I presume it's to prevent random accounts spamming the database with fake songs? At least if you have to do 500 reviews before adding songs and albums there's a more likely chance that the person adding them is adding things that are legitimate.
If you need someone to add songs or albums to the site's database, I'm happy to help out with that
Only certain people have the ability to do so. I think of our Australian members Daniel09 has the ability to do it, however you could also memo the member sophieellisbextor as they have the ability to add covers to the site iirc.