Circle map θₙ₊₁ = θₙ + Ω − (K/2π)sin(2πθₙ) mod 1. Arnold tongues are regions in (Ω, K) space where the winding number is rational p/q (frequency locking). At K=1 the tongues cover the entire line (Devil's staircase). Watch phase-locking in real time and see where your parameters sit on the tongue map.