Alternatively you could go back to your normal repertoire and ask yourself if there are any happy songs with which you have fallen into the modern practice of slowing them down till they can barely drag thenselves along. I have heard people sing the delightfully cheery little love song Heather Down The Moor as if it was Die Moorsoldaten!
Also for an object lesson in upbeat singing listen to recordings of Charlie Wills; this includes probably the world's only upbeat performance of Barbara Allen.