the events calendar update the word event
add_filter( 'tribe_event_label_singular', function() { return 'Concert'; } );
add_filter( 'tribe_event_label_singular_lowercase', function() { return 'concert'; } );
add_filter( 'tribe_event_label_plural', function() { return 'Concerts'; } );
add_filter( 'tribe_event_label_plural_lowercase', function() { return 'concerts'; } );