back in the days of recording from a record to a tape, to learn a part, we had to learn by ear and find out the hard way if the bass was not tuned to standard pitch, or if the speed of the record player was ever so slightly out.
Great training for the ear, which I almost completely lost when I had a couple of years out. Took me a while to get it back - use it or lose it.
I do wonder if it makes a difference to those who have always learned songs from clicking on a YouTube video and having it all on a plate (as it were)?