Is there any way to create or upload your own songs? It looks like a very polished app, but I'd like to be able to create my own songs, or even cooler, edit son

Is there any way to create or upload your own songs? It looks like a very polished app, but I'd like to be able to create my own songs, or even cooler, edit songs to see what they might sound like if played differently. Excellent job with the app. I will probably be downloading it soon.