Wood is the constitutive material of a wide variety of musical instruments and therefore contributes to their global behaviour, “quality” and identity, may it be acoustical, technical or aesthetical. This talk aims at synthesising the various aspects of wood science (physics-mechanics, botany, perception of wood) that can explain the traditional choice of material in instrument making, but also that can contribute to finding alternative solutions. A focus will be given to cases where wood properties are expected to contribute to the instrument’s acoustical response. The different levels and criteria of wood selection within variability can be categorised as: (i) organological families and parts/functions; (ii) cross-cultural comparisons; (iii) choice of species through makers’ traditional knowledge; (iv) empirical/perceptual qualification of wood pieces within a species. Furthermore, the fact that wood properties are variable within a piece or stock, and also depend on hydrothermal environmental conditions, must be taken into account. Ultimately, the choice of material can be considered as essentially multi-criteria, based on different structural, physical and mechanical properties of wood, in relation to “goals” which imply trade-offs between feasibility of instrument building (availability and workability of wood), physical-mechanical stability, aesthetic concerns, and of course acoustic response of the finished instrument.