Kodály had reasonable success with this approach across the world: https://www.classical-music.com/features/musical-terms/kodal...

His idea was to begin with one's voice as a musical instrument, so one would interact with music directly at first, learning the theory and the notation along the way.

The lady quoted in the article agrees with you but also seems to support why I thought of Kodály in the first place:

  > "Eleven years of piano lessons taught me something about playing the piano 
  > but almost nothing about music," she has said. "I was skating on the 
  > surface. If a child is shown a written crotchet they have no physical 
  > understanding what’s behind that. Kodály musicianship puts petrol in the 
  > tank in that it gives them a profound experience of music-making, through 
  > the voice, building up a repertoire of songs and giving them the 
  > unconscious knowledge of pitch-matching, walking the pulse, rhythm, 
  > phrasing and improvising – before making it conscious."

So you will not be touching the piano before all of this takes place and you will be learning the fundamentals and theory, even if in a playful way.

Playing a classical instruction you would normally do that. Maybe you learn how to hold, change reids, do scales first but without theory you can't read notes or understand what to do with them. Without reading notes you can't play songs off of sheet music.