The sounding elements in these instruments are very thin spring-steel bands a few feet long. They are given a bit more rigidity by a slight crease running the length of the band. This stiffens them enough that they can be mounted upright without flopping over. Here’s a description of one of the instruments shown on this page: The bands can be sounded by plucking with a fingernail near the base or striking with a small, hard beater such as a heavy nail, producing a pitched sizzle. Tuning for specific pitches in this configuration is difficult, but I did manage to get a limited number of related pitches, as can be heard in the sound clip. …And a description of the other: The bands on this one are flimsier and more prone to flexing, bending over and doing wonderful visual dances. This gives rise to highly variable and bendy tones, sometimes playing out over as much as 30 or 40 seconds after being activated as the band creases and uncreases in flexing.