Mark Farner is at it again...
https://www.ultimate-guitar.com/news/general_music_news/grand_funk_frontman_recalls_how_led_zeppelin_shut_his_band_down__threw_them_off_tour_because_they_outshined_them_as_opening_act.html
Hopefully it's just at start...
If all three are involved, here's hoping for unseen photos from their personal collections and it's not aimed at the baby boomers ($$$).
Otherwise Zzzzzzzzzzzzz