Most real instruments are nonlinear and resist simple filter-cascade modelling

Evidence

Unfortunately, many instruments are non-linear and such modelling is not possible. For example, in the trumpet, the air pressure affects the vibration of the lips in a complex manner that cannot be modelled by simple convolution. Also, the modelling of the dynamic control of the pitch brings an additional non-linear component to the system. This means that it is easier to model separated sounds with a constant pitch than an instrument whose physical state changes all the time, or, in technical terms, the frequencies of the resonances of vibrating structures change due to the playing of the instrument. Nevertheless, these effects can be numerically modelled in the time domain, which, however, may result in complicated models (Bilbao, 2009; Smith, 2010; Välimäki et al., 2006). — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 681

Categorization

• XREF: The linear-vs-nonlinear instrument modelling split connects to physical modeling synthesis literature (Smith, Bilbao) that underlies modern software instruments.