The correlations between the outcomes of pairs of spin component measurements on particles in the singlet state exist and can be observed independently of any a priori given frame of reference. We can even construct a frame of reference that is based on these correlations. This observation-based frame of reference is equivalent to the customary a priori given frame of reference of the laboratory when describing real Bohm-Aharonov experiments. J.S. Bell has argued that local hidden parameter theories that reproduce the predictions of Quantum Mechanics cannot exist, but the counterfactual reasoning leading to Bell's conclusion is physically meaningless if the frame of reference that is based on spin component measurements is accepted as the backdrop for Bohm-Aharonov experiments. The refutal of Bell's proof opens up for the construction of a viable hidden parameter theory. A model of a spin h/2 particle in terms of a non-flat metric of space-time is shown to allow the predictions of quantum mechanics in the Bohm-Aharonov experiment to be reproduced, without introducing non-locality.