Tom Ervin, Professor of Music at the University of Arizona was attending a conference for music teachers in New York. While at the conference he purchased a talking metronome. A metronome is a device for counting the beats in a song. Before Tom and his son boarded their flight home, Tom hefted his carry-on bag onto the security-check conveyor belt.

The security guard's eyes widened as he watched the monitor. He asked Tom what he had in the bag. Then the guard slowly pulled out of the bag this strange looking device, a six-by-three-inch black box covered with dials and switches. Other travelers, sensing trouble, vacated the area.

“It's a metronome," Tom replied weakly, as his son cringed in embarrassment. “It's a talking metronome," he insisted. “Look, I'll show you."  He took the box and…