An Automatic Soundtrack Generator permits merger of a sound track that is independent of the external sound source, while either recording or playing a video sequence. The torsion bar engages the swing bar in a direction transverse to sliding movement to prevent undesired movement away from abutting contact with the swing bolt. A stabilizing post is provided that includes a base slidably mounted with the elongated channel and a spine post projecting from the base through the channel and into the recess when the articular surface is in contact with said bearing surface. A first control gate is formed adjacent to the first charge storage medium adjacent to the first channel surface and a second control gate is formed adjacent to the second charge storage medium adjacent to the second surface. The boom can be retracted when not in use to reduce the volume it occupies. Meanwhile, a received radio-frequency modulated signal is fed to the mixer 8 for down conversion, and the thus-obtained signal is fed to an IF band demodulator 10 so as to restore an information signal.