Summer means festivals, catching some of your favourite artists and, if you’re lucky, a bit of sunshine.

But it’s all about the music, right?

Not quite. It’s also a chance to rock your favourite band t-shirt, whether it’s one you’ve just bought from the merch stand or one that’s seen better days.

They used to be a way to signal your impeccable taste, but recently more and more High Street and fast fashion brands have been selling music t-shirts.

Primark recently released their latest range including Green Day and The Rolling Stones, and other fast-fashion brands such as H&M and BooHoo – which released a collab with punk band The Offspring, have been getting in on the action.

You can usually get them for a fraction of what you’d pay at an official merch stall, making them more accessible for a lot of people.

But there can be a lot of snobbery around them, particularly if they’re worn by someone who’s not familiar with the musician on the shirt.

Does it actually matter, though?

There’s probably no-one better to ask than the bands, so BBC Newsbeat trawled through the mud at Download Festival to speak to and up-and-coming acts to find out what they think.

Pop-punk band Busted, who released their first album in 2002, say much has changed since they got together.

Bassist Matt Willis says it’s easy to get hung up on what people wear, but says: “We’ve never really followed fashion, we’ve kind of just done our own thing.”

Frontman Charlie Simpson says he wouldn’t personally wear the designs of a band he doesn’t know, but doesn’t care if other people do.

“If you like a band logo, then power to you. Who cares?” he says.

“If you like it, wear it,” says Matt.

“There’s bigger problems in the world,” adds guitarist James Bourne.

Busted were selling their own t-shirts at Download, and told Newsbeat they’d be happy for anyone to wear them if the design appealed.

Merch can be a big source of income for bands when sold at gigs, especially as getting royalties from music becomes more complicated.

But buying from venues and festivals can be expensive.

Lucas Woodland, frontman of rock band Holding Absence, says as a kid he couldn’t afford music merch.

“You can walk into H&M and buy a Smashing Pumpkins shirt for, like, eight quid,” he says.

“That’s amazing!”

But he says he understands the frustration of fans and there’s a fine line when it comes to wearing band shirts.

“These are bands that have saved people’s lives, these are bands that mean the world to people,” he says.

Knife Bride singer Mollie Clack and guitarist Sean Windle say there are two sides to the argument.

“Sometimes fashion and music can interlink,” says Mollie.

“Some t-shirts just look cool.”

She confesses to wearing t-shirts featuring black metal bands she doesn’t know because she likes their designs.

“I will call myself out,” she says.

On the other hand, Sean says it doesn’t fill him with joy when he walks into a shop and sees a Slipknot t-shirt.

But Mollie says it could inspire curiosity.

“Someone might buy their top and go on to listen to their music off the back of it,” says Mollie.

There’s another good reason to look beyond the design, as pop star Zara Larsson found out.

She had to apologise for wearing an outfit featuring album artwork by Norwegian metal act Burzum, who’s known for holding neo-Nazi views.

Pop-punk band Bowling For Soup’s frontman Jaret Reddick tells Newsbeat his 11-year old son wears a lot of band merch.

He says random people will approach his son and ask him to “name three songs”.

Jaret says his son can do this but that strangers testing him is “douchey”.

The band, who recently celebrated their 30th anniversary, sell merch with trendy designs so anyone might like them.

“I want the person to wear it because it’s a cool shirt,” he says.

“If people ask about the band then that’s a bonus.”

Friends Ciaragh, Katie and Gemma braved Download’s weather at the weekend, wearing band merch under plastic ponchos.

They tell Newsbeat they’d never wear a band t-shirt if they aren’t a fan.

Katie says it infuriates her when people wear merch from an act that they don’t know or like.

“Don’t wear the band if you don’t know them,” she says, passionately.

Ciaran, Will and Joe, all in their early 20s, were also at the festival and tell Newsbeat they think a band t-shirt is just a design and anyone can wear it.

The lads say they sometimes wear merch of musicians they don’t know because they like the look of it.

There’s a lot of criticism of fast fashion brands over their impact on the environment, and it’s a concern for Blaize Ashton-Jenkins.

She runs her own fashion company, Blaize’s Uniques, turning customers’ used band t-shirts into dresses.

Most of what she gets sent is original merchandise from shows.

“The culture behind them is you go to a gig, you go to a festival, you get the t-shirt,” she says.

Blaize, 31, from Hitchin, Hertfordshire, says she “completely understands” why fast fashion brands selling band t-shirts affordably has become a thing.

“I think it’s a way for anyone to be able to get hold of what they want to wear,” she says.

“As the owner of a slow fashion brand, it’s obviously not a great thing,” she says.

“I’m never for fast fashion.”

Blaize does think you shouldn’t wear a band t-shirt if you don’t know a group’s music, but that people can get too hung up on the topic.

“You shouldn’t have to dress a certain way because you like certain music,” she says.

Listen to Newsbeat live at 12:45 and 17:45 weekdays – or listen back here.