Beyond AI age, virtual world enlarges its influence. But from artistic and ethical point of view, the relationship between REAL and _VIRTUAL is definitely important. Looking back to the life of L. van _Beethoven as a musician, he had handicap in hearing and would like to overcome this with the utmost of the "innovation" of the day, round 1800. Aside from those hearing aids, his use of metronome was revolutional to the history of music. Mechanical training method after Beethoven changed clearly --- mostly by his pupils like Czerny and following generations .. Franz Liszt, Theodor Leschetizky ... But also from music thinking's point of view, Beethoven's interest in innovation yields rich musical invention. We would explore this fertile possibility from STREAMM's view point: Science, Technology, Reflection, Ethics, Arts, Mathematics and MUSIC.