In this video we have a comparison of the metallic (wet, cold) sound of Bali with the woody (dry, warm) sound of 5 Crosses.
3 Crosses, circa 1990
Oscillators: 3 pairs of iron plates (each with different lengths), fixed on a threaded rod and isolated from the stand with rubber pipes.
Radiation: 3 fiberglass cones, one for each pair of plates.
Gamut: Xentonal system with 6 tones (carefully designed over years of development).
The aim of this piece of the Baschet Pedagogical Instrumentarium is to have 6 different mid-range pitches with a woody, warm, full timbre in contrast with the other pieces of the Instrumentarium.
Fixed Plates DIY kit, après-Baschet, by Martí Ruiz, 2012
Oscillators: 3 pairs of iron plates (each one having a different length), fixed on a threaded rod and isolated from the stand with rubber pipes.
Radiation: Each pair of plates is radiated by a cardboard cone, tightened against a plastic funnel (low-cost mounting invented by François Baschet). These cones generate a warm and dry sound.
Gamut: Found xentonal, note the particular timbral qualities – warm and wood-like – and the unique tonal qualities: when one plate is struck, the other also vibrates, so each pair produces a cluster chord, perhaps not offering a very clear tonality, but varied enough to explore and enjoy the combinations of tones.
For this DIY kit we used some pre-drilled plates from a reserve of material that François Baschet left to the Barcelona University Sound Sculpture Workshop. We had no particular aims aside from experimenting with the plates. The sound of the clamped plates does not emerge until the plates are tightly bolted. The resultant gamut was a found tuning created by the locations of the pre-drilled holes.
For fixed plates, the location of the mounting point plays an important role in creating certain vibrational behaviours. Creating symmetry by clamping the plates in the middle allows for resonance to occur: vibrations in both halves of the plate reinforce each other, resulting in longer decay times. Creating asymmetrical differences in length by clamping the plate anywhere other than the center point creates different wavelengths on each side and, therefore, two different sounds. In this case, the resonance of each side is less than with symmetrically clamped plates. We can hear this in the Baschet Pedagogical Instrumentarium instrument Etoile. We can also hear asymmetrically-fixed plates in Chollet B, found in the Multitimbral Settings examples.
Lotus Sanza, circa 2000
Oscillators: 8 thin plates clamped on one end to a single rod, free to vibrate on the other end, displayed radially.
Activation: Finger plucking
Radiation: A bent stainless sheet adds reverberation and enhances certain resonances, even adding distortion when the plates are activated with enough intensity.
Gamut: One full octave of diatonic F# major scale. Displayed low to high. We can hear some overtones of some plates that resonate louder.
Here we can once again hear the primary vibrational mode of those plates, the fundamental pitch and the less prominent overtones, bringing a metallic nuance to the timbral qualities. The subsonic bands of frequency we see in the spectrum are produced by the excitation of the overall system, despite the small size of the piece.
In this case, the brothers likely used a conventional seven-tone diatonic scale in order to appeal to private collectors. The empty space in the middle of the speaker is often reserved for a unicorn standing on its rear legs or any other figurine François Baschet would make by folding sheet metal. He made several of these, and this particular piece remained unfinished (with no unicorn) in his Paris workshop.
The use of fixed plates as the Baschet brothers used them is unique, as far as we know. Flat rectangular plates or bars have been used in many locations and cultures, typically mounted in such a way that they are freely suspended at their nodal points. This allows their fundamental idiophonic mode of vibration to dominate, as can be heard with xylophones, marimbas, glockenspiels, vibraphones, gamelan gangsas, etc.56 The Baschet also made use of freely-suspended plates in many pieces, usually coupled to resonating pipes, demonstrating their familiarity with with this common paradigm of freely suspended plates as well as their unique implementation of fixed (not freely suspended) plates.
We have chosen to include the fixed plates of the Baschets as part of the odontophone mounting settings because they share some of their complex behaviour. This setting is diametrically opposed to the one used in freely-suspended plates. Here the plates are clamped, either through-bolted in their center or in any other section of their length, and their natural tension and vibrational modes are completely modified. While the usual freely-suspended plate vibrates with an antinodal region in its center, when a plate is tightly bolted in its center, a nodal point is imposed there, creating a forced tension that imposes a new wavelength to the freely-vibrating end of the plate. This fixed region is also where the vibrations can be transmitted to a coupled radiator. In other words, this system converts freely vibrating plates into a tongue (or a tooth), since they are firmly clamped, and the vibrations will be transmitted to any other solid in contact with that clamping bolt. Even when those plates feature wider surfaces and are more likely to radiate vibration to the air, some of the vibrations will be immediately transferred to a gum or to a radiator, adding natural resonant formants and frequency responses and radiating the lower frequencies that otherwise would not be radiated.
Also, when several plates are bolted together, complex systems are created. Again, as with our big comb-like rod percussion instruments, several interactions may occur, none of which would occur if the same plates were freely suspended. The most relevant issue here is that the sound becomes completely different when the plates are clamped: the resulting pitch, as well as timbral envelope, of the same plate changes, depending on whether it is suspended freely or tightly clamped. As we have said, the coupled radiators also add their own colours, so, when considered as a compound system of oscillation, there is a certain modularity regarding sound design in fixed plates that we do not find in free suspended plates, offering a wider range of new combinations to explore. The Baschet used balloons, cardboard, and metal cones as radiators for fixed plates, each one offering its own timbral qualities.
Bali, circa 1965
Oscillators: 11 iron plates, fixed symmetrically on a threaded rod.
Radiation: Two stainless steel cones that not only radiate the sound originating in the plates but also add their own bright resonance and reverberation, creating a somewhat subaquatic sound.
Gamut: Xentonal, approximately (A, C#, D#, F#, G#, B, D, F#, A, C#, F#) but not tuned to any particular temperament. We can see there are pitches that appear in two different octaves, so there has been a careful process of tuning, by adjusting different plates, with the intention to create a cohesive gamut.
Etoile, circa 1990
Oscillator: 3 iron plates asymmetricaly mounted (through-bolted) with a bolt, directly connected to the radiator.
Radiator: Hard cardboard cone, isolated from the floor by rubber strips along the cone perimeter.
Gamut: Xentonal system based upon 6 tones.
The aim of the Baschet Pedagogical Instrumentarium is to avoid conventional music scales, offering a distinctive sound with each instrument and creating an overall palette of timbres. Etoile creates 6 different mid-range sounds, all sharing the same timbre.
To conclude this section, we have added an example of much thinner plates, metal strips so thin that they can be bended with one's bare hands. Offering yet another connection to plucked thumb pianos, François Baschet designed a series of small-sized pieces for more humble collectors, using steel strips bolted on an axis and connected to steel reverberating speakers, which can work in the same manner with all the elements we have described above.
5 Crosses, circa 1990 (revision of a 1960’s original)
Oscillators: five pairs of iron plates clamped on five threaded rods, forming five crosses, isolated with rubber pipes from the stand.
Radiation: Each pair of plates is radiated by small fiberglass cones that produce a characteristic warm sound.
Gamut: This is a very distinctive gamut, besides its warm timbral aspect, because it is apparently tuned to a singular pentatonic scale in the range of two octaves, each cross containing the same tone in the two octaves. However, two of the crosses feature shorter intervals, closer to a major seventh, with the inherent emotional tension that this interval creates, so the scale is like a singular extended xentonal pentatonic scale or an unnamed scale with seven tones. The tuning of each pair is approximately D3+D4 // F3+E4 // G3+F#4 // A3+A4 // C4+C5.
Figure 67. 3 Crosses, part of the Baschet Pedagogical Instrumentarium, courtesy of Andreu Ubach, picture by Martí Ruiz. (Ruiz 2015).
Figure 66. Video recording of Bali and 5 Crosses. Source: https://www.youtube.com/watch?v=bcVhLCp-niA
Figure 70. Audio recording and spectrogram of the clamped plates on Fixed Plates DIY kit. (Ruiz 2015).
Figure 71 and 72. Video L'étoile - l'instrumentarium pédagogique Baschet. Source: https://www.youtube.com/watch?v=THxXmSCMxfQ. Still picture by Martí Ruiz. (Ruiz 2015).
Figures 73 and 74. Lotus Sanza and detail of the oscillators clamped to a single rod. Pictures by Martí Ruiz.(Ruiz 2015).
Figure 76. Spectrum of a fragment of the final resonating sounds from the Lothus Sanza audio file, showing the saturated sounds produced by the overdriven metal radiator. (Ruiz 2015).