Name the city most likely to serve as backdrop to the following scenario:

It’s 11 PM; you walk out into the late-summer breeze, and you can’t decide where to go first. You’re just cab fare from any of the blowing sessions that are starting up, and even though you’ve had your ear to the ground, you’re still not sure which musicians will be heading where. You’ve been hearing about Steve Nelson, the hot new vibist: think he’ll be sitting in with Paul Wertico, the drummer from Pat Metheny’s band, or might he opt for a cross-generational matchup with Buck Hill, the legendary saxist from D.C.? Is Jack Walrath, the trumpeter, in town an extra day–and is there a chance he’ll hook horns with Shorty Rogers, his brilliant counterpart of three decades earlier? And d’ya think the trailblazing trombonist Albert Mangelsdorff might really sit in with–McCoy Tyner?

It’s possible that such a scene could take place in Paris: the French love le jazz Americain, and there are enough world travelers passing through on any given night to populate the above fantasy. Another good guess might be the small city of Perugia, Italy, where each year the Umbria Jazz Festival offers a swirl of postmidnight performances in small rooms that border cobblestone streets. And a popular guess might be New York, where such events are theoretically possible even though the city’s jam-session heyday–when jazz clubs crowded onto each other and “lights up” meant dawn–was 45 years ago.

But choice (d)–Chicago–is the correct one, folks. This weekend, as the Chicago Jazz Festival blows through Grant Park, no less than three clubs will be offering after-the-fest jam sessions. That’s three times as many as ever before, and because of a quirk in this year’s festival schedule there’ll be plenty of players to go around. Usually, the festival includes only a few big bands (jazz groups of ten or more); this year, there are six, and the traffic jams backstage will only benefit the postpark activity.

In other words, there’s really a second jazz festival this weekend, taking place at Joe Segal’s Jazz Showcase, at the Southend Musicworks, and at the Bulls jazz nightclub: an after-hours jam festival such as Chicago hasn’t seen in decades. And while many modern musicians have distanced themselves from the stereotypical jazz life-style epitomized by these packed and noisy early-morning smoke-filled sessions, it remains true that such events can bristle with an intimate excitement that’s simply unavailable on a larger stage, much less the one in Grant Park. The music is still about improvisation; and improvisation still does its reaching and growing in the less formal confines of the after-hours session that remains the music’s laboratory.

The abundance of after-fest activity is new this year, but the concept isn’t: it actually began in 1980, the second year of the Chicago Jazz Festival, when a group headed by percussionist Kahil El-Zabar inaugurated late sessions in a loft space at 14th and Michigan. These events–really “a separate concert series adjacent to the festival,” says El-Zabar–ended in 1982.

It was a few years later–either ’85 or ’86–when Joe Segal began using his Jazz Showcase to host a more conventional after-hours series, which evolved from a fortuitous coincidence. For the first ten years of the jazz fest, most of the visiting musicians were booked into the Blackstone Hotel, which also houses the Showcase. “They were stopping down from their rooms and falling in” to play with the regularly featured Showcase attractions, Segal recalls. Finally, Segal began organizing the sessions by hiring a house band and inviting selected stars to join in; the result has been a steady stream of SRO evenings during the jazz fest.

As in years past, you can count on straight-ahead blowing at the Showcase, with the foundation being laid by quartets led by the impeccable reedman Frank Wess (Friday), tenorist Buck Hill (Saturday), and west-coast saxist Bill Perkins (Sunday).

Southend Musicworks is trying a different tack this weekend. Like the Jazz Showcase sets, these will be “organized jam sessions”–invited guests only, and no open mike–but Southend guru Leo Krumpholz wants to keep things a good deal less structured. “Instead of having a rhythm section for the whole night and contracting extra soloists, we’ve invited a couple of different bassists and drummers for the core. . . . I want to keep the whole thing loose, to orchestrate it from the seat of my pants with those musicians who are hanging around.”

In keeping with Southend’s philosophy, the music will be the most adventurous and progressive in the city, and those “hanging around” could include members of the Muhal Richard Abrams Orchestra, the Mingus Epitaph band, trombonist Mangelsdorff, and the extraordinary flutist/composer James Newton.

Meanwhile, you can expect some of the more eclectic- (and electric-) minded festival players to gravitate toward the Bulls, where drummer Paul Wertico and guitarist Bobby Broom (a veteran of groups led by Sonny Rollins and Kenny Burrell) will lead a quartet on Friday and Saturday. Sunday, Malachi Thompson’s Freebop Band will hold down the fort. Bulls general manager Guy DiCara has been spreading the word through contacts in New York and figures to draw those sitters-in that don’t really fit the other two sessions. “Hopefully, this will be another outlet for some of the younger performers.”

In all the hubbub, we may even see another night like September 4, 1987, when the Showcase stage could barely contain a trumpet cavalcade boasting Wynton Marsalis, his Jazz Messengers successor Terence Blanchard, the hard-bop veteran Bill Hardman, and the superb Brian Lynch. Unable to join the other sardines filling the aisles of the club, I listened from the lobby with a New York reedman who had just played at the park. “For one week a year, this place is like New York,” I observed. “Are you kidding?” came his reply. “This never happens in New York.”

Tonight through Sunday night: Sets at the Bulls, 1916 N. Lincoln Park West, start at 9:30 and cost $8; 337-3000. Sets at the Southend Musicworks, 1313 S. Wabash, begin at 10 and cost $5; 939-2848. Sets at the Jazz Showcase, 626 S. Michigan, start at 10:30 and cost $10; 427-4300.

Art accompanying story in printed newspaper (not available in this archive): illustration/Slug Signorino.