While listening to the 1-18-42 show today which is all music (due to Carole Lombard's death), I was thinking about the previous comment here of Dennis' singing being passe in his own time as compared to others like Frank Sinatra.
I grew up in the 70s with parents that listened to easy listening/beautiful music radio. Lots of Mantovani, Frank Chacksfield, London Symphony Orchestra, Percy Faith, etc. Sometimes the Carpenters. My parents loved it, had it on in the car all the time, so I listened to it as well. And I even developed a taste for it, and later worked at one of the last such stations in the country (WEZV - Fort Wayne) as it started to change its format to avoid the dreaded "elevator music" label. Don't tell anyone, but I saved a few of the old broadcast reels from oblivion before they were sent back to Kalamusic for disposal. Wound one up on my reel-to-reel a few months ago and it was like an emotional time capsule.
So while there were the Rolling Stones, Jimi Hendrix, the Grateful Dead, Supertramp, Pink Floyd, and whoever else may have been considered "cutting edge" at that time, my parents were happily listening to stuff that could be described in comparison as dated, schmaltzy, dreamy, stuffy, and square. Just a matter of taste.
So I'm sure that there were many people who might have preferred Dennis' traditional singing to some more progressive artists of his time.
And just as Dennis sang some current songs, I was once stunned to hear an easy listening station broadcasting the London Symphony Orchestra's rendition of "Material Girl".