The initial sounding elements here are steel bars bent to form an angle, so that their vibratory patterns are more like those of tuning forks than bars. They are further shaped by grinding or kerfing in ways that bring their most prominent overtones into more coherent intervals with one another than they would otherwise be. These bent bars are played with percussion mallets. But that’s not the end of the story: each bent bar hangs from a musical string which is tuned to agree with the fundamental of the bent bar. Magnetic pickups are positioned to pick up the sound of the string, so that the amplified sound is that of the bent bar and its overtones as filtered through the string. The sound of the instrument is most effective when you can hear a blend of both the amplified sound from the pickup and the natural acoustic sound coming from the bent bars. There are 23 of these bar/string combinations, tuned diatonically in the lower octave and chromatically in the upper octaves, for a total range of two octaves and a third.