They are among the thousands of Phish fans who will descend upon New York for the band’s so-called Baker’s Dozen, a 13-show residency at Madison Square Garden that starts Friday and ends Aug. 6. They will go with the wide-eyed hope that the band performs a silly stunt, covers an unexpected song or jams for 30 minutes on a tune it hasn’t played in decades.

To catch these moments, to be part of the Phish experience for four hours, is why fans have followed the band since 1983. I would know. For the past 20 years, I’ve driven, flown and bused to the corners of the country to catch a piece of Phish magic. I’ve snaked along a single-lane road for seven hours in the Florida Everglades for Phish’s millennium concert. I’ve been rerouted to and then stranded in the Salt Lake City airport after seeing the band in Las Vegas. I’ve stood up to my ankles in mud on a country field in Maine during a rainy Phish festival, long before “festival style” became a hashtag.

Now, Phans can create memories in New York — a city that upon first glance seems contrarian to the free-spirited jam-band culture. The city will be awash in Phish-themed workouts, hazy after-parties, children’s concerts, daytime boat cruises, art shows, flea markets and even tailgate-style gatherings. After all, fans will need something to do the other 20 hours of the day when Phish isn’t playing.

“We’re going to see several hundred thousand people come in over this run,” said Peter Shapiro, who promoted the Grateful Dead’s Fare Thee Well shows in Chicago two years ago, and is the publisher of the live-music magazine Relix. “You’ll feel it at museums. You’ll see it in restaurants. There’s going to be way more tie-dye.”

Mr. Shapiro is also the owner of Brooklyn Bowl in Williamsburg, Brooklyn, and the Capitol Theater in Port Chester, N.Y. He’s turning the Phish marathon into a family-friendly affair at both spaces with a children’s concert series featuring the music of Phish. “Many Phish fans have young children,” Mr. Shapiro said, “so we figured this is a good way to keep the vibe rolling into the next afternoon.”