Projected-period vs. GaiaG-band amplitude (see text) of low- and intermediate-mass O-rich AGBs in the LMC (left) and SMC (right). The green diamonds indicate RGBs and faint AGBs; the blue symbols indicate low-mass O-rich AGBs; and the cyan squares indicate intermediate-mass O-rich AGBs. The dashed lines represent approximate separations between the three distributions corresponding to 1O mode periods, fundamental mode periods, and LSPs.