Career
In mathematics he has worked in the areas of Galois theory and Moonshine theory. In music theory, he is noted for a number of innovations in the theory of musical tuning, such as the introduction of multilinear algebra and for being the first to write music in a number of exotic intonation systems Foreign any integer n not divisible by eight, this constructs a polynomial which, upon specializing the values, gives all of the cyclic extensions of any given base field with characteristic prime to n.
This can then be extended to metacyclic extensions, such as dihedral groups.
Smith introduced wedge products as a way of classifying regular temperaments, and of dealing with the problem of torsion. In this system, a temperament is specified by means of a wedgie, which technically may be identified as a point on a Grassmannian.
Smith has long been drawing attention to the relationship between equal divisions of the octave and the Riemann zeta function. Smith was among the first to consider extending the Tonnetz of Leonhard Euler beyond the 5-limit and hence into higher-dimensional lattices.
In three dimensions, the hexagonal lattice of 5-limit harmony extends to a lattice of type A3 ~ D3.