Grant & Martha,
OK, so I listened to the podcast. "Cellar door" has got to be a meme. Its meaning is not beautiful, nor is its sound. In fact, I had never heard of that two-word combo described as being beautiful. I liked Martha's suggestions of "lullaby" and even "microchip." Guess it has something to do with how the word rolls off the tongue.
I read somewhere (don't recall the source) that the single most "beautiful" word in the English language was "illumination." I like that. It does indeed roll off the tongue. Plus, it has a beautiful meaning as well. And then there's the additional meaning, from the pre-Gutenberg era, of literally making a word beautiful by the addition of color or gold or silver leaf. I was unable to locate the source online, but I really do like that word.
Kinda' on the same topic, I always felt the word "cacophony" was somehow evocative of its meaning. It is an ugly (sounding) word.
Interestingly, none of these words makes Robert Beard's Top 100 List.
I have to wonder if the supposed beauty of "cellar door" is because it reminds someone of "celadon" (a type of gray-green glazed pottery) or some other word with real-world associations to something beautiful. Like "celesta" or something.
In the category of words with repulsive meaning but a beautiful sound, I nominate colostomy.
Glenn, I'll see your colostomy and add diarrhea.
The source of the words cellar door being beautiful might very well have come from a French person because the words cellar door sounds eerily like seul l'amour or seul adore. Which means only love in French.