Want to play Tommy Mottola — back when being Tommy Mottola was fun? Long Island City-based music site Amie Street — freshly funded by Amazon — is rolling out a Facebook app that lets you set up a fantasy record label based on its mostly-indie music catalogue. Your “label score” goes up and down as songs get more or less popular. The better you do, the more credits you can earn toward mp3 downloads. Looks like it could be both fun and rewarding — a rarity among Facebook apps. The tricky part: finding artists you’ve heard of in their 100,000-song library.