We study the propagation modes of right circularly polarized electromagnetic waves traveling parallel to an external static magnetic field H-ex in one-dimensional (1D) periodic metallic composites, i.e., the heliconic band structure. Although the dielectric function of metal in this case depends on frequency omega, the characteristics of the heliconic band structures are very similar to those of the photonic band structures of 1D periodic dielectric composites. The heliconic band structure can be easily controlled by H-ex. Thus it is possible to control the defect modes of helicons and the coupling modes of the helicon-transverse sound wave in 1D periodic metallic composites using H-ex. We also discuss the localization of helicons in 1D disordered metallic composites.