Yup. When you had a keyboard player, you tuned to them. In our case, it was to the Hammond CV organ. Later, he got a real piano, and he had to tune it to the organ, as well. Once we lost the keys, we were lucky that one of the guitarists had a Peterson strobe tuner. I want to say that someone came out with a lower cost tuner (maybe Korg), but I can't remember whether we had one.