In 1807, Joseph Fourier announced his mathematical equivalence of finite functions with an INFINITE series of simple harmonic functions; this meant any complex tone could be summed (analyzed) into an infinite series of frequencies (base plus overtones). De Broglie's suggestion of a moving point particle being mathematically equivalent to an infinite series of plane wave (2D harmonics).
Schrodinger generalized this analysis of the finite atom (spatially & temporally limited) into its mathematical equivalent: 3D spherical harmonics.
So, what's the big deal? Why do mathematicians reify their representations?
Particles are NOT waves.