I realize it's been a few months now, but maybe you still want the answer. The riddle as published in Omni magazine in 1980 said the "LOUDEST OF VOICES" and not the "sweetest sound"; the complete riddle given then was:
I'm the loudest of voices in orchestra heard
But yet in an orchestra never was seen;
I'm a bird of gay plumage, but less like a bird
Nothing in Nature ever has been.
Touching earth I expire, in water I die,
In earth I lose breath, I can swim, I can fly.
Darkness destroys me and light is my death;
I can't keep alive without stopping my breath.
If my name can't be guessed by a boy or a man,
By a girl or a woman it certainly can.
My answer, in a tie with about 17 other people, if I recall correctly, was voted as the most likely answer. This is it, based on the wording Omni printed:
Wilberforce's Young Whale
Bishop Sam Wilberforce gave man a riddle,
And for over a century many did fiddle,
But few could perceive that the key to it all
Was the loud "voice" in orchestra, non-musical.
The accents in or'-che'-stra are where I am heard,
But seen there in person? That would be absurd,
For I am an "orca" – that's Latin for "whale",
As proclaimed by two syllables in a clue to this tale.
For "any young animal", Webster's slang is: "a bird",
But for me to have feathers would, again, be absurd.
Although, as a "young" whale, a "bird" I might be,
I would look strange roosting up in a tree.
And as for gay plumage, my feathers be one –
The plume from my blowhole, iridescent in sun.
In water I live, so in water I die,
Unless touching beach, I expire when dry.
I fly through the air in great leaps from the sea,
And swimming, of course, just comes natural to me.
An air breathing mammal, my breathing must cease,
Whenever I dive to find krill for my feast.
And into the depths of the earth I do dive,
In search of the food that I need to survive.
When breath I have lost, to the surface I swim,
To the world up above, though my future be dim,
For man in my hunter – he kills me on sight,
And he uses my whale oil to brighten his night.
In that sense, 'tis true then that "light is my death",
And "darkness destroys me", so my epitaph –
I think it should say, quite appropriately,
"My death is light – for the nineteenth century".
Though women have frequently mentioned my name,
Their meaning and I are not always the same,
For when they say "wale", they speak not of me,
But rather of fabric, or baskets they see.
So, what of the last clue? What were we to find?
That gender wasn't certain; what was, was mankind.
by Bill Velek, December 1980