I was so impressed by Andreas Burgess' In The Courtyard of the Beloved that I solicited advice from my good friend Anamitra Chakladar, who suggested that the time lapse frames may have been produced by using an intervalometer.
The device is a remote switch with a cord and a self-timer, interval timer, long-exposure timer, and exposure-count setting feature. The timer can be set anywhere from 1 second to 99 hours, 59 minutes, or 59 seconds. Ignoring the more expensive Canon model on B&H, I found one on eBay for less than $50 including shipping.
The brand new device, called JJC TM and made in China, arrived last night in perfect condition. Its accompanying manual is somewhat sparse in details, so I'll have to figure it out on my own (which I prefer anyway). Once I do, I'll try it out on the traditional opera singers in Chinatown or some similar activity.
PS: I figured how to work it in a few minutes...without the manual's "help".