Detailed calculations show that the two most important dynamical problems in the formulation of a theory of star formation (namely, the angular momentum and magnetic flux problems) can be resolved in that order by magnetic braking and ambipolar diffusion, respectively, relatively early during the collapse of an interstellar cloud or fragment. Although the physical processes involved are complicated and highly nonlinear and the formal solutions are mathematically nontrivial, they can often be elucidated by exact analogies with small-amplitude, transverse waves on strings, by a mechanical (or quantum mechanical) “leaky” system of N coupled oscillators, and by spinning coaxial metal disks joined by rubber bands and sharing (as well as losing to an external medium) energy and angular momentum (see Mouschovias and Morton 1985a, Astrophys. J. 298, 190; 1985b, Astrophys. J. 298, 205, Mouschovias and Paleologuo 1979, Astrophys. J. 230, 204; 1980, Astrophys. J. 237, 877).