  It is shown that interference effects between velocity and density of states,
which occur as electrons move along open orbits in the extended Brillouin zone,
result in a change of wave functions dimensionality at Magic Angle (MA)
directions of a magnetic field.
  In a particular, we demonstrate that these 1D -> 2D dimensional crossovers
result in the appearance of sharp minima in a resistivity component Rzz,
perpendicular to conducting layers, which explains the main qualitative
features of MA and Angular Magneto-Resistance Oscillations (AMRO) phenomena
observed in low-dimensional conductors (TMTSF)2X, (DMET-TSeF)2X, and
a-(BEDT-TTF)2MHg(SCN)4.
