Under the spreading chestnut tree, where I held you on my knee.
We'll be happy as can be; under the spreading chestnut tree.
The first time through, sing the words as written. The second time, omit the word "tree" and instead imitate tree branches with upward and outward hand motions. The next time, also omit "nut" and tap the top of the head. Then, omit "chest" but pat the chest. Then, omit "spreading" and instead spread hands apart, etc. [Replace "happy" with a scowl and growl.] At the finish, almost half the song will be gestures.