Noelle, who also saw the special, mentioned on her article for Saburo Kitajima's（北島三郎）"Guitar Jingi"（ギター仁義）that there was one segment when Masaaki Hirao（平尾昌晃）, Akira Kobayashi（小林旭）and Sabu-chan showed up for a bit of banter with the first two guys doing some retro cosplay of sorts. I definitely have to agree that the first two guys cut quite the dashing figure according to those old photos in the background. Kitajima wasn't exactly the most handsome of fellows but I think the growing admiration for him was due to his down-to-earth man of the people demeanor.
But I'm taking care of Hirao's part in the trio's appearance on August 8th. I've only really known his contributions in kayo kyoku far more through his songwriting than in his singing, although I used to listen to his duet with Yoko Hatanaka（畑中葉子）when they sang the karaoke fave "Canada kara no Tegami"（カナダからの手紙）. Plus, he was the fellow who helped introduce Agnes Chan to the Japanese public in the early 70s.
I found out through his J-Wiki article and then later through one of Noelle's articles that Hirao started out as a rockabilly singer with that de rigueur pompadour. The song that he sang on "Omoide no Melody" that night was a 1960 single of his own making "Miyo-chan" (Little Miyo). The original version has that 1950s swinging Western lilt that reminded me of some of my really old days when a lot of my TV viewing included old shows such as "Gunsmoke", "Bonanza" and "Hee Haw", especially that last one since it was a country music show. However, Hirao's lyrics could be just as appropriate for an enka tune as the singer pines for that titular girl from the 2nd year of high school back in his hometown. Alas, the lad punishes himself for not having enough gumption to show his hidden feelings for little Miyo, and there is an opportunity missed. Back on the lonely road...
I only found the above video purely by chance. But apparently the music-comedy group The Drifters did their own cover of "Miyo-chan" through some movie with Cha Kato（加藤茶）taking on Hirao's protagonist part. We get to see the lyrics visualized!