  We describe an interpretation of quantum mechanics based on reduced density
matrices of sub-systems from which the standard Copenhagen interpretation
emerges as an effective description for macro-systems. The interpretation is a
modal one, but does not suffer from the range of problems that plague other
modal interpretations. The key feature is that quantum states carry an
additional property assignment in the form of one the eigenvectors of the
reduced density matrix which evolves evolves according to a stochastic process
driven by the unmodified Schrodinger equation, but it is usually hidden from
the emergent classical description due to the ergodic nature of its dynamics.
However, during a quantum measurement, ergodicity is broken by decoherence and
definite outcomes occur with probabilities that agree with the Born rule.
