Echelle diagrams of the power spectra of two mixed-mode stars (KIC 5955122 and KIC 12508433). The power spectra are normalised by the background and smoothed over 3 μHz. The l = 1 ridges are broken and pass through the l = 0 − 2 ridges; the plot on the left hand side shows an example of a mixed-mode star with the l = 1 modes not aligned along a ridge but still passing through the l = 0 − 2 ridges. The plot on the right hand side shows a faint l = 3 ridge at 32 μHz.