Top and bottom plots represent respectively the threshold pressures and threshold frequencies given by the locus of the Hopf points (blue) and the locus of the saddle-node bifurcation points (orange and green) with respect to the lips’ resonance frequency in the case of the C-contrabass tuba, E♭-bass tuba, F-bass tuba, B♭-euphonium and B♭-bass saxhorn. The circles identify the local minimum of blowing pressure for each note, namely the pedal note (PN), the ghost note (GN), and the second regime (R2). The dashed portions at the ends of each U-shaped patterns in the case of the C-contrabass tuba mean that these curves still exist above p_m = 2 kPa, but the computation was simply not performed above this value of mouth pressure. (a) C-contrabass tuba. (b) E♭-bass tuba. (c) F-bass tuba. (d) B♭-euphonium. (e) B♭-bass saxhorn.