Alvorada na floresta tropical W513 was commissioned by the Louisville Orchestra and written in 1953. In form it is an overture whose performances take eight to eleven minutes.

Its form is predictable, though the music itself is anything but. Hushed and mysterious string sounds clearly picture the darkness under the canopy of the forest as the sky begins to lighten. Strange, shadowy rustlings and slithers move with unexpected speed against the slow basic pulse; nocturnal creatures are heading for home and day-dwellers begin to stir.

The first real melody is a trumpet solo that may herald the gradual infiltration of light from the rising sun into the perpetually shaded realm, or one can imagine the scene from high in the branches, as the sun's beam appears. From that point, there is a gradual increase of musical density, speed, and loudness. Whenever one listens to the melody, one is always aware of the constant strange figures, like creatures who move just in the periphery of vision, or only betray their motion by a disturbance to a branch. In the midst of this, cries and calls break out on various instruments. Now it is a group of horns that seems to be waking up the life of the forest.

The final part of this three-part structure seems to have the whole forest restored to its daytime life. A constant moving pulse animates the texture and brings the work to a glowing conclusion.