Try this, a slow manual method. Create a ball, say in photoshop, with a transparent background, and save the file at the size that your Canvas requires. (Use tiff or jpg if in PAL to avoid the dreaded corruption by .psd files). Add it to a video track in FCE as a clip. With keyframing (use the Motion tab in the Viewer), move the ball in time with the words as they are sung. Then use the bezier handles in the track (ie., path) created by the keyframes in the Canvas to tweak the movement.
You could, with some effort, create the effect. You might need to make the photoshop image (which becomes the clip) unusually wide, with a smaller increase in the height, with the ball near the bottom, to allow movement of the clip from extreme left to extreme right and slightly up and down.