  Using the example of a two-dimensional macroscopic model glass in which the
interparticle forces can be precisely measured, we obtain strong hints for
resolving a controversy concerning the origin of the anomalous enhancement of
the vibrational spectrum in glasses (boson peak). Whereas many authors
attribute this anomaly to the structural disorder, some other authors claim
that the short-range order, leading to washed-out Van Hove singularities, would
cause the boson-peak anomaly. As in our model system, the disorder-induced and
shortrange--order-induced features can be completely separated, we are able to
discuss the controversy about the boson peak in real glasses in a new light.
Our findings suggest that the interpretation of the boson peak in terms of
short-range order only, might result from a coincidence of the two phenomena in
the materials studied. In general, as we show, the two phenomena both exist,
but are two completely separate entities.
