Top: horizontally polarised wave field ξ_∧ as a function of time and space for a coronal rain blob forming at s = 0.48L with a mass corresponding to μ = 0.25. The loop has length 100 Mm, Alfvén speed V_A0 = 1000 km s^-1, and an inclination of θ = 50°. Also, τ₁ = 500 s and t_ramp = 100 s. The curve is the path s_p(t). Bottom: time evolution of the 5 first harmonic amplitudes ξ_{∧ ,n}. The dashed curves are the equivalent for τ₁ → ∞ and t_ramp = 0 s.