Answer:
"On top of spaghetti, all covered with cheese. I lost my poor meatball when somebody sneezed. It rolled off the table, and onto the floor, and then my poor meatball rolled right out the door. It rolled on the sidewalk, and out in the street, and then my poor meatball was a crushed piece of meat."
A Different Version
(mostly the same, but after rolling out the door it went like this:)
"It rolled down the sidewalk / And under a bush / And then my poor meatball / Was nothing but mush. // But then the next summer / It grew to a tree / And now my poor meatball / Makes meatballs for me."
A Third Version (complete)
On top of spaghetti,
All covered with cheese,
I lost my poor meatball,
When somebody sneezed.
It rolled off the table,
And on to the floor,
And then my poor meatball,
Rolled out of the door.
It rolled in the garden,
And under a bush,
And then my poor meatball,
Was nothing but mush.
The mush was as tasty
As tasty could be,
And then the next summer,
It grew into a tree.
The tree was all covered,
All covered with moss,
And on it grew meatballs,
And tomato sauce.
So if you eat spaghetti,
All covered with cheese,
Hold on to your meatball,
Whenever you sneeze.