Lost peice

I have just spent 3 hours creating a peice of music, i saved it, i never deleted it, then your app crashes, so it forces me to close the app. I go back on, my peice is absolutkey no where to be seen. There has to be a way i can recover it? If not I will be leaving terrible reviews for the app as this is absolutley ridiculous, this is my music assigment due for tomorrow, and I have never been so furiouis ever. Why did it not save when i clicked save, why is it not there. please help im desperate