I wear these at all gigs i go to (and also in the cinema and crowds). they are made specifically for that environment so don’t lose sound quality, its the same sound just a little quieter. they come in a little case you can put on your key ring and also have loops you can put a string or chain through to wear them round your neck
(Loop is the brand) They’re very subtle when you’re wearing them and they work well at concerts at least. Different size tips for different size ears make them comfortable. NY Times recommends Soundcore Space One and Earfun Air Pro 4 if you want to try noise cancelling gear on a budget. If you have the money for Bose or Sony, go for those. I recommend playing white noise with them to help mask sounds.
The Quiet version - great for concerts or sleep. The Engage version - great for conversations in loud restaurants or parties. These really mute a lot of cross noise and make it more comfortable to be out and about if loud noise drains you. They’re comfortable and come in nice colors. Each pack includes a cute and durable case and multiple sized plugs so you can choose the ones that fit you best.