resonant spectra consists of two fundamental elements, the instruments, and the sculpture. the instruments are driven by two different sustaining techniques; two through physical contact with felt smoothing discs, and another through magnetic copper coils. at a very low rate, the instruments sweep through frequencies with a 60 degree offset via a servo mounted tuning peg. the sculpture was designed using Helmholtz formula for a resonating spherical cavity. Each pair of resonators are tuned to a harmonic series of low E (41hz) and up to the 6th harmonic. The reasoning behind the orientation of each pair of resonators can be explained through acoustic propulsion: when the resonating frequency of a resonator is being produced in a space, a vortex shedding pushes air out of the openings of the resonator, resulting in rotational motion. the goal of this installation is to activate the rotation of the spectral sculpture with the resonating frequencies in the room. a subwoofer is placed in the center of the room to help reinforce lower frequencies. in order achieve rotation, levels much reach up to 110db.