"To join the chorus" means to become part of a group or community, typically in support of a common cause or idea. It suggests that someone is adding their voice or contributing their opinion to a larger discussion or movement. Full definition
I do my part in joining the chorus of those sharing experiences of pregnancy loss — despite silence, despite stigma. (pregnancyafterlosssupport.com)
Those of us who don't join the chorus tend to keep quiet or ignore it all, figuring we've got better things to do than read such stuff. (firstthings.com)
Join the chorus with your own favorites, if they aren't among the ten chosen here. (wrightonfilm.com)