New York, Nu York: Kipot at the Concert

This year I don't think I saw any movies in the theater. Not one. I had hoped to see two or three but just never got around to it. But I have attended around 20 rock 'n roll, jazz and other types of concerts. It may be the opposite situation with most people, but I love to see music live. And I have a wide range of tastes so the concerts I saw this year have really run the gamut of styles. 
In 2017 alone I have seen heavy metal concerts (Metallica, Iron Maiden with Ghost, Scorpions); classic rock (Paul McCartney, the Grateful Dead spin-off Dead and Company); old-school punk rock (Green Day); blue grass (Bela Fleck and the Flecktones); newer jam bands (Tedeschi-Trucks Band); old-school folk (John Hammond Jr.); jazz stalwarts (Ramsey Lewis); outdoor festivals (the Warped Tour); klezmer (Golem, at the Golem Art exhibit opening night) and a few others, some in passing or on special days such as the Summer Solstice-Make Music New York daylong festival.
I saw all these shows in New York City, Long Island and New Jersey (in addition to standing and listening to many good buskers in Dublin, Ireland and London, England while my family and I were vacationing). And no doubt, at each show there were Jewish people in attendance. But aside from the Golem performance, where nearly everyone in the crowd was Jewish, the show with the most obvious Jewish presence (as evidenced by men wearing kipot and a few women wearing modest skirts) was none other than... Dead and Company.
Is this surprising? Perhaps to some people. Perhaps not to others. But this past Sunday evening at the venerable Madison Square Garden, my husband and daughters and I were among thousands of DeadHeads (or at least fans) who filled the seats for the 50-plus year old band that mixes rock 'n roll, folk, blues, jazz, and whatever. And I must say that I noticed more kipot at this concert than at any others in 2017.
Perhaps there was a minyan during the intermission. (I didn't know of it.) It would have been easily arranged; seriously, I saw more than a dozen youngish and not-so youngish men wearing kipot at this show, and a few women who seemed dressed in a modern-Orthodox style.
It is no secret that the Grateful Dead have had quite a following in the greater Jewish community. And this was a show attended by a New York crowd. And Jews may feel more comfortable wearing their kipot at Madison Square Garden, or even at a Dead show (after all, one of the drummers is Jewish-- Mickey Hart). But it still seemed remarkable to me that this was such a "Jewy" show. The band did not play Hava Nagila. There were no wordless niggunim sung. Yet there were definitely more out and proud Jews here than at the heavy metal concerts, for certain. 
And I do know many less-observant Jews who like or love the Dead, and who have seen them this year or many times in the past. What is it about the Grateful Dead that appeals to many Jews? (For comparison, I did not see a single hijab wearing woman  at this Dead and Company show, nor at the one we attended in late June.However, I have seen a few obviously Sikh young men at a Dead show in the past.) Is it the musical hybrid? Is it the colorful spectacle? Is it the general knowledge among fans that the Dead never play the exact same show each date in a tour? 
I don't have a definitive answer; not even a guess. But there usually seem to be some kipot at Dead concerts. Are you one of them?