When electrons are subject to a potential with two incommensurate periods,
translational invariance is lost, and no periodic band structure is expecte
d. However, model calculations based on nearly free one-dimensional electro
ns and experimental results from high-resolution photoemission spectroscopy
on a quasi-one-dimensional material do show dispersing band states with si
gnatures of both periodicities. Apparent band structures are generated by t
he nonuniform distribution of electronic spectral weight over the complex e
igenvalue spectrum.