Sexual assault, unwanted harassment and inappropriate behaviour at music events are common but incidents are rarely being reported, according to campaigners.
A victim called Emily said she was dancing at a gig when a person reached between her thighs and grabbed "really aggressively" at her crotch.
She thought it may have been a "mistake by someone jumping around" but then discovered similar incidents happened to others, including her friend, and "someone was systematically doing this".
She said: "I'd always thought of gigs as kind of my safe space. I think that was probably why I felt so violated and uncomfortable when it happened."
On social media, Safe Gigs For Women (SGFW) receives daily tweets from women sharing their stories of unwanted harassment and worst.
Tracey Wise set up the group after she was sexually assaulted at a gig in June 2015.
She said: "Sexual assault, sexual crimes are some of the most unreported crimes that we face in society. We're not really sure how many women are facing this when they go to see live music.
"However social media has been the tool that's allowed us to talk about this and to get in touch with people who say they are experiencing this."
SGFW has a small team that works with bands and music venues to highlight the problem.
Sarah Claudine, a volunteer with the group, said: "There are very few gigs that I've been to where something hasn't happened."
As Ms Wise explained: "It's about being proactive, changing the attitude and mind set of people who think that this might be acceptable."
Folk-punk singer Frank Turner is one of the artists they work with.
He said: "I must confess to being slightly naive about it, I suppose, or out of the loop. There was an incident at one of my shows and I found that absolutely horrifying.
"It enraged me, so I got in touch with Safe Gigs For Women and asked what more we could do to make something happen.
"I'm very protective about rock and roll, about gigs and about punk rock and my shows.
"I want them to be a safe place and for everybody to enjoy themselves, lift the weight of the world off their shoulders for a few of hours, that sort of thing, and the idea of people behaving like animals in that context is just really upsetting to me."
Romilly Martin, managing director of East London arts venue Village Underground, said: "The most important thing is that you speak up, don't be quiet about it."
She said most venues nowadays will have trained their staff and want to be made aware of the problem.
She said: "Don't feel ashamed, don't feel embarrassed, don't feel like you're going to be bothering anyone.
"Our staff are all trained to be able to handle the situation, eject someone if it's needed or if it's very serious and it requires the authorities, then we have instant reports and CCTV and if it becomes a criminal matter we will make sure we take the steps to deal with it."
She added: "In reality if it happens once then once is too much. It's really important that we can have a dialogue about this...and that we stamp this kind of issue out.
"It shouldn't be happening at all, everyone should be able to have a good night out and feel it's a safe space."