Since the beginning of this year, some of the most loyal fans in the history of rock music have been ticking the days off the calendar, lying in wait to be a part of a long strange trip that began in the 1960s.

The surviving members of rock band the Grateful Dead—Bob Weir (67), Phil Lesh (75), Mickey Hart (71) and Bill Kreutzmann (69)—announced in January that they would be re-forming to play a final set of concerts, titled Fare Thee Well: Celebrating 50 Years of Grateful Dead. Trey Anastasio of the popular jam band, Phish, will take the place of the late lead guitarist Jerry Garcia. The response from fans, often referred to as Deadheads, was overwhelming—500,000 people applied online for tickets for the three shows on 3-5 July at Soldier Field in Chicago, US. By way of comparison, when the era-defining Woodstock Music & Art Fair took place in 1969, where the Grateful Dead performed, 400,000 attended.

But then, the Grateful Dead is unlike any other rock band. In a career spanning from 1965- 1995, when Garcia died unexpectedly, the Dead had only a single top 10 hit. Neither did they have the demeanour nor the looks of a rock band. Yet, for its fans, and they are legion, the Dead epitomize American music like no other. Melding folk, blues, country, bluegrass, rock ‘n’ roll and jazz, the Dead were sonic explorers, taking these various strands of American roots music to places where it had never travelled before. The Dead could invoke avant-garde composers such as John Cage and Charles Ives just as easily as they could dig into the old timey Americana of hillbilly pioneers, The Carter Family. As the late concert promoter and impresario Bill Graham once remarked, “They’re not the best at what they do; they’re the only ones that do what they do."

The Dead regularly subverted roles that are normally assigned to members of a rock band. Lead guitarist Jerry Garcia had an almost other-worldly melodic sense that owed a lot to banjo playing, his original instrument; he was also an accomplished pedal steel guitarist. Weir’s unique harmonic phrasing and use of chord inversions was unlike the garden-variety rhythm guitarist. With their telepathic interplay, Weir and Garcia would often come across as duelling guitarists trading melodies and riffs. Bassist Lesh, rather than keeping time, was like another lead guitarist, launching into his own melodic explorations. And the drummers—Kreutzmann and Hart—had this symbiotic attitude where their contrasting styles of playing complemented each other.

The Grateful Dead were devotees of More Than Human, the cult 1953 science fiction novel by Theodore Sturgeon. The book is about a group of people who are able to “blesh" (blend and mesh) their abilities and consciousness to form the “homo gestalt"—a sort of group organism. At gigs on a good day, the Dead could come across as this single entity, intuitively riding the twists and turns that their music would take. “I’ve always felt from the very beginning that we could do something that was, not necessarily extra-musical, but something where music would be only the first step," Lesh once said in an interview. “Something maybe even close to religion in the sense of the actual communing."

Sen is one of the fortunate ones from India who has managed to catch quite a number of Dead shows, at venues such as the fabled Winterland Auditorium in San Francisco, which closed the year he arrived in the US. He was also witness to concerts at the Radio City Music Hall in New York in 1980, the basis of the live acoustic album, Reckoning. “I don’t remember it musically," Sen says about the first concerts he attended. “I remember it as an occurrence. On your first exposure, you get distracted by ancillary matters rather than the music."

Weaned on Indian and Western classical music from a young age, Sen was surprised by the Dead when he heard them while in school. “There is the Dead and then there is rock ‘n’ roll," he says. “Rock ‘n’ roll was a gas; Cliff Richard was a gas; Presley was a gas, but this was an exploration, an aural journey into the subconscious. My first reaction was that this was an electric string quartet."

Sen’s fascination with the Dead has been sustained, partly because the band’s songs evolved over a period of time. “A Dead song in 1972 is not the same song in 1977; or the 1970 acid-drenched gigs, which was a time when the Dead were out there every evening storming the gates of heaven," Sen says. “Then you have a new sensibility, a lyricism developing after the Europe tour—1973 onwards. They have this laid-back sensibility and a classic example is Playing In The Band. How it changed. It was completely like, let’s lie back and let heaven come to me.."

Ironically, Sen has heard more of the music since the band stopped performing. “The amount of Grateful Dead music that was around when he died, well…there’s ten times more available today," he says.

Kartik Sri Ram, the 43-year-old CEO of a manufacturing firm in Bengaluru, has a similar story to tell. His first brush with the Dead was in 1990 when he joined BITS Pilani and heard strains of China Cat Sunflower coming out from one of the hostel rooms. “There’s enough of the Dead’s music to be never worried that there wouldn’t be any more. I have listened to more Dead in the last 10 years than I heard from 1990-2005, thanks to YouTube," he says. But Sri Ram admits that he was “pissed off" when he heard of Garcia’s death. “I was arriving in the US for my MBA in July 1995 and my buddy bought tickets for the gig at the Boston Garden in September 1995," he remembers. “But a month before the show, Jerry died and the show didn’t happen."

Having missed the bus 20 years ago, Sri Ram jumped at the opportunity when the band announced the gig dates in January. “I have tickets for 4 July. I was part of two groups of Deadheads who were trying to buy tickets. One of them didn’t get any tickets. Another got a few," he says. “But there is a chance that I may not be able to attend. And there are many in that group who will be eternally thankful if I don’t make it."

Due to skyrocketing demands, tickets for the Soldier Field, Chicago shows, originally priced from $59.50-$199.50(around 3,700- 12,700), have touched the $8,000 barrier. Soldier Field was the venue of the final Grateful Dead concert on 9 July 1995, but the band has added shows on 27 and 28 June at Levi’s Stadium in Santa Clara in California. In a public letter, they said, “Since we made the decision to go back to Chicago to say our final goodbye, it has become clear to us that we first need to return to our beginnings, where we first said hello—to each other and to all of you."

There are some like Sen, who will not bother to attend the concerts, and does not listen to music by the members of the Dead after 1995. “I don’t have anything to do with them; I closed my chapter." But for fans like Sri Ram, it’s now or never. “Some friends in the US are going with a sense of trepidation—an expectation that they may be disappointed," he says. “Too bad for them…I am just looking forward to the trip."