if you just send it to a record label it will never get heard. That's just being realistic, they dont have time to listen to all of the demo's they are swamped with, plus they dont listen to them to avoid lawsuits from artists suing them and what not. They ALSO aren't going to be big on using their imagination to kinda invision what the female will sound like or how the guitar and piano will sound like.
Your best bet would be to find some local talent, and really make sure they are good and work out some deals with them. If you land it right, you could get everything for free (except studio time). Female talent sings for free, they get a song that they can use as their demo and the piano/guitar players get recognition as well through a good sounding recording. You in tern, get your idea realized in musical form in which you can then showcase to the right people.
Now this is the important part, finding those right people. You're going to have to meet and know someone who is in a position or has a friend that is in a position to take on your project. It's all about relationships and networking, finding those contacts and following up on everyone until one of them fall through. Don't get discouraged, but it'll probably take a good amount of contacts until something falls through
Just understand that it's a numbers game almost until you find that right person in a label that will take you seriously. So NOT doing anything, or only networking with afew people and banking everyhting on that isn't going to get you far. Go out and talk to people, let everyone know what you do. Someone will eventually know that person that can get you in and it will happen.
Hope this helps,
Peace!!