The answer is this by Microsoft. Songsmith can generate a song for you. The commercial film which made by developers is completely different with what I expected. And look! It’s a MacBook Pro!
You know Miku HATSUNE? It’s a Japanese awesome song generator. But these two softwares have a different approach. Songsmith generates music it self but Miku HATSUNE generates a vocal part. This one reminds me how Japan and US are different.