Nice work! If you are looking for ways to enhance this or complementary routes, one thing I was thinking about recently... As a musician, often I play songs I don't know the lyrics to. It would be cool to have an app that could follow along karaoke style with the words, as I sing and as the band plays. Right now I clip a phone to the mic stand, but after a lyric or two, I lose my place. This is probably multitudes more complex based on every "band/vocals" sounding different, but just something I was thinking about.