Bifurcation diagram obtained with harmonic balance method and numerical continuation: L²-norm of the acoustical pressure depending on the blowing pressure parameter γ for the low written D♯ fingering of an alto saxophone. Thick lines: stable solution, thin lines: unstable solutions. Black: equilibrium, green: 1st register regimes, red: 2nd register regimes. Multistability zones are shaded: light yellow where 1st and 2nd register coexist, darker gray for equilibrium and 1st register. Blue circles specify the location of bifurcations. Vertical black lines correspond to those in Figure 6c, and (from left to right) to phase diagrams 7a–7c.