A sound object is modeled as a collection of vibrating sub-structures
Less structures to compute than the mass-spring system
Each substructure has
a set of frequencies and damping coefficients for the substructure's resonating nodes
coordinates describing the mode's shape
Allows combining different sub-structures together to create new instruments
Can be estimated and computed from geometric and material modeling
Often calculated from measurements of objects
Often modeled in with biquad resonators