Examples from the Web for tra
Tra comes from a Sanskrit word trayate that means "to liberate."
Frasquita and Mercedes join in the "Tra la la la" of the refrain.The Complete Opera Book|Gustav Kobb
Occasionally the accusative of direction is used after tra, when this seems useful for emphasis, or to remove ambiguity.
He made his friend repeat the performance, called him a daisy, and tra la la'd to his heart's content.Two Knapsacks|John Campbell