As mentioned previously, and reported on by the immortal "The Other McCain" (scroll down on the opened link to hear a seminal performance by Orriel)
Orriel Smith is, beyond any argument, the possessor of the most beautiful voice ever recorded. Pure in tone...no need to gild the lily, the original analysis is here which links to her songs.
The old saw that advises "nobody remembers the name of the second person to fly the Atlantic" has some validity (who was it BTW?) but in the case of "The second most beautiful voice ever recorded" that is not quite the case.
Margot Sylvia is, sadly, gone but far from forgotten. The Tune Weavers were, basically, one hit wonders with "Happy Happy Birthday Baby, being their one and only great hit.They actually mined it a number of times with subsequent variations (Merry Merry Christmas Baby) but basically the first was it. I actually like the flip side a rollicking version of "Old Man River" too.
The aspect which made their hit stand out, apart from the excellent baritone saxophone intro, is of course Margot Sylvia's voice.
In common with Orriel, Margot has a most beautiful pure tone. From the pitch-perfect first note to the soaring chorus, she sings effortlessly. Her voice, which the first word "happy" illustrates, sounds like the purest note on a musical instrument-almost as if the sax which delivered the opening low notes suddenly switches into a higher register but with the same, almost reedy tone.
Margot was blessed with having a backing group who who were perfect for her clear sharp voice-much as Judith Durham (yes, she is the third most beautiful voice ever recorded) had with The Seekers.
Here is Margot Sylvia in full flight (linked to YouTube in case the embed below doesn't operate). I must have listened to this a thousand times since I bought it on a 78 rpm all those years ago.
NB; "I Remember Dear" is a lovely example of perfect pitch and this is a lovely comment on that site
"There will never be another singer like Margot Sylvia....it is so sad that she is not with us anymore. I listen to "come back to me" every night, over and over again. Does anyone out there know if there is a Margot Sylvia fan club?