Hi I’m Alex and I play the violin. The sounds sound so real but you forgot G3. Missing a few other notes too. You forgot the note b for the e string. I liked that you put the sharps. Also, for the C note on the G string, it’s not C4 it’s C3! Also, you can put D3 because you can play D on the G string. Also, you can’t play half notes. Every time you press a key on this app, it’s a quarter note.