Spherical harmonics Y_ℓ^m(θ,φ) are eigenfunctions of the spherical Laplacian: ΔY = −ℓ(ℓ+1)Y.
They form an orthonormal basis for L²(S²). The deformed sphere shows r = 1 + s·|Y_ℓ^m|.
Audio tone: frequency ∝ √(ℓ(ℓ+1)), like quantum energy levels on a sphere.