RADIO NIGHTS were magical evening hours before televison, during the era of network radio, when the whole family would sit together, listen, and, strange as it may seem, watch the glowing radio. It wasn't just the dial that glowed, if you looked at the back of the radio, the vacuum tubes were glowing too! On NBC, all of Monday evening was devoted to music, lighter than classical fare, often from motion pictures and stage musicals. The orchestras and singers performed "live" for the broadcast, musical standards were very high, and so was the quality of sound, if you had a good radio. Lincoln Mayorga's unique program offers light American music of the era, some featuring the piano and some with just the orchestra. If you close your eyes, you and the audience will be that family, sitting around the radio - listening!