As television, the Internet and other forms of electronic media continue to vie for the short attention spans of audiences across the country, Garrison Keillor's “A Prairie Home Companion” remains resiliently dedicated to the archaic simplicity of broadcast radio. Created in 1974, Keillor's old-time inspired variety show is as popular as it's been in years, highlighted by its American folk-music guests, satirical skits, tongue-in-cheek parodies of old radio dramas, and fictitious sponsors and products. While typically recorded from the Fitzgerald Theater in St. Paul, Minn., the respected staple of the airwaves takes its show on tour across the country from time to time. Making a stop in Richmond, “A Prairie Home Companion” is scheduled to perform at Lewis Ginter Botanical Garden on Friday, Aug. 13, at 7 p.m. $55.