Comment by pierrec

For metallophones used in Gamelan music, I don't think the key difference is emphasis on higher vs. lower overtones. Rather, their overtones don't follow the harmonic series but are still well-defined. Their tuning goes along with that, and it works given that particular non-harmonic timbre, but wouldn't work with western classical instruments, which tend to approximate the harmonic series in their overtones. In all cases the lower overtones remain the most audible and the most important ones for tuning and finding consonance.