That works when you already have certain bands in mind. Sometimes you’ll just have a free weekend and want to know what’s happening around the city, and artist alerts won’t show you everything. You can check the lineup for rock concerts in New York here: https://myrockshows.com/location/173-new-york-ny/ . Look through the next few weekends and see what catches your eye. A bill with one familiar name is usually enough reason to give it a shot.