With two more reunion shows, the pioneering jam band foils scalpers and appeases shut-out fans while looking at a haul of $50 million. But is the end really near, or will a new lineup appear?

When the "Core Four" surviving members of The Grateful Dead -- Bob Weir, 67; Phil Lesh, 75; Mickey Hart, 71; and Bill Kreutzmann, 68 -- announced Fare Thee Well, a trio of final shows in Chicago set for July 4-6, no one expected a backlash from fans. After all, the Dead had pioneered the complicated craft of preferred ticketing, launching its own Grateful Dead Ticket Services in the '70s to accommodate tapers, fan club members and Deadheads looking to attend shows in multiple cities, a common rite of passage for the band’s followers.

So when 210,000 tickets sold out within an hour on Feb. 28, and then minutes later showed up on secondary-ticket sites with astronomical markups -- one pair was going for a cool $1 million, another for $100,000, many more for $10,000 (though StubHub spokesman Glenn Lehrman tells Billboard that such auctions are not “legitimate asking prices”) -- shut- out fans cried foul loudly.

“After Chicago blew up, the band got to see firsthand, and hear from friends and family, how many people couldn’t get tickets for the Soldier field shows,” says Fare Thee Well chief architect Peter Shapiro, 42, who, along with Madison House Presents, is promoting the event. One million ticket requests flooded in online through super-speed bots, and 400,000 snail mail envelopes were received as well. “We had big expectations, we know the power of the band, but the scale I don’t think anyone could have predicted,” he adds. “Ticketmaster said it was the biggest demand ever for a single concert -- a whole new level. Half a million people [in the queue] at four tickets each, times three... we could have sold 6 million tickets.”

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Acknowledging the situation and the “realities of the current times” in an open letter, the members blew off some steam, writing that it's "hardly comforting when you're shut out of tickets and your only option is inflated prices on secondary ticketing websites. That would piss us off, too." Their solution: book two more shows with the same guest lineup -- Phish guitarist Trey Anastasio, Jeff Chimenti (keyboards) and Bruce Hornsby (piano) -- on June 27 and 28, adding another 130,000 tickets, and modernize the idea of lining up for a wristband to guarantee a spot in the ticket-purchasing queue with an online lottery. The venue: Levi’s Stadium in Santa Clara, Calif. -- “only 12 miles from where the Dead first met in Palo Alto 50 years ago at Dana Morgan’s Music Store,” says Shapiro, taking pride in being able to bookend the band’s start and finish in nine days.

Santa Clara requests were taken after the shows were announced on the Grateful Dead channel on SiriusXM. Even if some diehards groused about the addition of the two California dates after Chicago was billed as the last stand (which it remains) and as an exclusive event (which it now is not), the overwhelming majority voted with their wallets, with “hundreds of thousands” of requests, according to Shapiro, who declined to provide a specific number (one source puts it at 300,000).

The on-sale was orchestrated by Ticketstoday, formerly Musictoday, the direct-to-fan powerhouse founded by mega-manager (and Deadhead) Coran Capshaw (Dave Matthews Band), now part of Live Nation, which logged fans’ credit card numbers and let them know on April 15 if they had won the lottery. Shapiro was impressed with the system, which has been used for bands like Phish, but never for an event of this magnitude.

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All went smoothly, and now with five sold-out Dead shows in the books, Fare Thee Well is on track to bring in $50 million in box office (more than most arena tours), plus as much as $8 million to $10 million in merchandise sales. Add a robust secondary market; sales of rooms, dining and travel; and tickets for other jam bands playing in town, and the reunion could easily generate $250 million in total revenue. Factor in the band’s take of pay-per-view fees (a package to watch all five nights runs $79.95 through Live Alliance), on-demand streams and live showings in more than 1,000 movie theaters, announced by Fathom Events on April 16, as well as clubs around the globe, and the Dead is very much alive.

Indeed, the numbers surrounding the group always have been astounding. Gregg Perloff, president of Another Planet Entertainment, who worked extensively with the band while a promoter at Bill Graham Presents from the 1970s through Jerry Garcia's death in 1995, recalls, “During the 1980s, the Dead would sell 130,000 tickets in Las Vegas while bands in second place like The Eagles and Paul McCartney would move in the 32,000 range. BGP would average over 80 shows between the Dead and Jerry Garcia per year just in markets west of the Mississippi [and] I only recall one show that was not sold out during this period. The loyalty of their audience was second to none."

Naturally, such staggering paydays are an argument for continuing to tour, yet the core four insist that Chicago, 20 years to the week after Garcia’s final show with the group, will be their final bow... as the Grateful Dead. Still, all this renewed energy leaves open the possibility of other incarnations involving new lineups of the band. One being worked on, according to multiple sources, is a fall tour featuring John Mayer. According to insiders, the trek is due to kick off in October, with the guitarist having already begun to jam in a rehearsal-like setting with select members of the group, chief among them Weir. But a rep for the band tells Billboard that it's "premature" to suggest an outing is being planned.

Shapiro declines to comment on the speculation, but cautions that any such tour would not go out under the Grateful Dead banner. “There’s nothing more coming,” he says. “I think you will see each of these guys continuing to do creative, cool things. Sometimes one or two may do something together. What you won’t see is the four surviving members together saying goodbye in this kind of way. This is it. Chicago is the end, and Santa Clara is leading into the end. But like a great Dead tune, it will evolve and they will wander around on their own.”

A version of this article first appeared in the May 2 issue of Billboard.