Here's a more complete Mountain Dew from another site.

REAL OLD MOUNTAIN DEW

Chorus:
Ah didlee ay dum
ah diddlee ay dum
Ah doo ray diddlee ai ay
Ah didlee ay dum
ah diddlee ay dum
Ah doo ray diddlee ai ay

Let grasses grow and waters flow
In a free and easy way
Just give me enough of that fine old stuff
that's made near Galway Bay
The police men from old Donegal
Sligo and Lietrin too
We'll give them the slip and we'll take a sip
Of that real old Mountain Dew

At the foot of the hill there's a neat little still
Where the smoke curls up to the sky
By the smoke and the smell you can plainly tell
There's poiteen brewin near by
It fills the air with a perfume rare
But betwixt both me and you
When home we go you can take a bowl
Or a bucket of the Mountain Dew

Now learned men who use a pen
Have wrote your praises high
That sweet poitin from Ireland green
is stilled from wheat and rye
Put away your pills, it'll cure all ills
Be ye christian, pagan or jew
Take off your coat and grease your throat
With a bucket of the Mountain Dew