Saci Perere is a remarkable little Brazilian nightspot -- not only for having survived for more than a quarter of a century, but also for having done so with never-diminishing energy. I think of the bar, which takes its name from a mischievous one-legged ghost in Brazilian folklore, as one continuous samba line, shaking and snaking its way through the underbelly of the city.

Even on my last visit -- at 10 p.m. on a Monday, the place was jumping. A special early show of chanson had just finished, and then it was samba time. Ono-san, the master, joined the band onstage, and together they launched into a soft and slinky set of Brazilian standards. A few of the regular customers instantly jumped up and grabbed makeshift maracas -- mostly small plastic bottles containing a few dried beans -- that can be found in ample supply near every table. They converged on the small strip of floor designated as the dancing area -- some of them also equipped with whistles, but all of them with contagious energy that spread through the house. The music may be smooth, but the reaction is usually manic.

All of the elderly, suited gents, who'd come for the early show, stayed. Many of them joined in the fun -- shimmying and cha-chaing with the huddle of dancers in front of the stage. If the dancers' energy reaches critical mass, a full-on samba line will spontaneously form. When that happens, a wild streak of revelers circles through the entire club -- including a brief tour of the kitchen to complete the loop.