Problem: For the Broadway production of Fosse, sound designer Jonathan Deans needed to get the dancer/singers, pit musicians, and onstage musicians on the same page tempo-wise.

Solution: Deans created Viz-Tones, a series of small boxes (2" long, 1/2" wide, and 1/2" deep) with two flashing LED lights, one red (for the backbeat) and one green (for the count), designed to enable the performers to visually see the beats from the orchestra.

Deans explains: "For 'Sing, Sing, Sing,' there's a band onstage and a band in the pit, plus three musicians in the dressing room. Keeping three different groups of musicians together, plus the dancers, was hard. There's a tempo track that runs in the background for the musicians in the pit, and the musicians onstage are wearing in-ear monitors, but the performers don't have them. So we put together these two flashing lights with just the right color and intensity to catch the eye, and set them to different frequencies, so everyone can count where they are in the bar.

"We put four of these around the stage, and four in the pit as well, because the musicians like them," he continues. "Not all of the musicians want to wear headphones, and shouldn't wear them; otherwise they're in Planet Zog, dreaming of something else. So the ones who don't wear them can actually see the lights beating as well."