In episode 1, when Yuuri skates to Viktor's Stammi Vicino, the background music is coming from Viktor's side, as he performs it in that year's GPF, meaning Yuuri was skating with no music.
The viral video that got posted had no music.
When Viktor Nikiforov first saw that video, it was silent. No music, none.
Which explains: "I was drawn to you because of the music... The way you skate is like your body producing music." --Viktor's line in episode 4.
