Pictures. Ticket stubs. Cell-phone videos. There are many ways to remember an epic concert, but one of my personal favorites is the concert t-shirt. According to Paste magazine, which just published 16 musicians’ reflections on their first concert t-shirts, the concert t-shirt is king.

There is actually a wikipedia page on concert t-shirts, which claims flat black is one of the most popular colors for concert tees. There’s even a twitter account, @bandshirtguy, that aims to “collect a picture of every band shirt ever made.”

The concert t-shirt fills many roles. These days, it’s often just a fashion statement. Sometimes people wear them because they think it makes them cool. Sometimes people buy them as a way of expressing their interests—a physical Facebook “like” you can display in real life. In the past, fans would buy a band’s tour shirt and wear it to the next show (though, these days that’s less kosher).

Toronto-based journalist Kate Carraway says the concert t-shirt served as a way to identify and align yourself as a fan of certain bands. She writes, “… before the long and dark era of fashionized and re-sold vintage concert shirts and vintage-styled concert shirts (objectively the worst), a concert t-shirt with a band you actually liked on it was the way that you publicly aligned yourself. It was critical that you listened to them, bought their music and went to see them, and here was your proof.”

This Keith Urban shirt features the stage design for his tour, an update on concert shirts that list tour dates.

Back in 1979, a special Led Zeppelin t-shirt even granted access to party backstage with the band to fans donning the tee. Last year someone paid $10,000 for one of these rare shirts. The buyer clearly wanted this souvenir.And to me, a souvenir or keepsake is the most important role of the concert t-shirt. Although I don’t own many concert tees (I spend all my money on the tickets), the ones I do own are wrapped up in memories.

My favorite is a t-shirt from Bonnaroo 2003. It was the second year of the now iconic festival. It was my first ever music festival. It was one of the best weekends of my life.

Even today, nearly a decade later, when I wear that shirt I remember carpooling through Tennessee in a van crammed with friends, food and camping equipment. I remember winding up in the back entrance, stuck in an endless line of cars on a one-lane road. I remember after hours of sitting in line, the van running out of gas. I remember walking nearly a mile to the closest gas station, filling up canisters and walking back to the van. I remember getting a prime spot for our tent, not too far from the stages. I remember the mullet-themed campsite names. I remember being front row for Nickel Creek. I remember losing my flip-flops in ankle-deep mud while watching Jack Johnson and Ben Harper. I remember gulping three cups of the sweetest (and most expensive) lemonade I’ve ever tasted. I remember waking up with the hot sun at 5 a.m. I remember brushing my teeth with bottled-water. I remember carrying toilet paper. I remember the sun etching a burn line where my bandana met my forehead. I remember cooling off in the fountain. I remember laughing uncontrollably with friends. I remember Bela Fleck, G. Love, the Roots. I remember bonding with fellow festival-goers. I remember stumbling into a tent and discovering O.A.R. I remember it all. And I owe a lot of those  memories to my shirt.

The t-shirt is the sort of memorabilia that you use often. It keeps your mind fresh, unlike a ticket stub you might have stashed away in a box or a scrapbook.

I think, Simone Felice put it best when he told Paste, “I guess to me [a concert t-shirt] never really feels cool until you’ve worn it in. Three-hundred washings, a few tears, some memories, ’til it fits like a glove and feels like an old friend.”