Wow, for me things that can't be physically represented (at a human scale anyway) such as most of mathematics, physics, and frankly music are fascinating, definitely feel real, can be explored, but yes, are beyond concrete representation.
Could one write a 16-part invention? I doubt it; certainly I think it would be hard to conceive of playing it, but I can "look into" a complex invention as I hear it and see how it could subdivide and get an idea of where that could lead. Certainly anything beyond the physically representative is to me sublime, and still able to trigger synesthesthetic response.