Intermediates
General mountain dulcimer or music discussions
The key part of @terry-wilson's comment below is the practice part. The fact is that if you can sing (not well, necessarily, but hitting something close to the right notes) then you can play by ear. If your brain can make the connection between the interval between two notes and the right amount to open or stretch your vocal chords, then it can certain make the connection between intervals between notes and distance on the fretboard. After all, on the fretboard, you have not only your brain making a theoretical connection, but the feel of your fingers and the vision of your eyes. So playing an instrument by ear should be three times easier than singing. The only difference? Most of us have been singing our whole lives, so we have decades of experience. Too few of us practice playing by ear.
And one problem with tablature is that it forces you to look at it instead of looking at the instrument. So it actively sabotages your ability to play by ear.
I have no doubt that there are a lot of people who right now are unable to play by ear. But that doesn't mean they can't do it. They just haven't tried enough and practiced it. Perhaps because I am self taught on most of the instruments I play (I took some guitar lessons the summer after third grade and piano lessons around that same time) I am amazed that people are afraid to play without tablature, without someone else telling them exactly what to do. Just put the instrument on your lap. Play something. If it sounds good, do it again. If it doesn't, try something else. Don't be too ambitious, just try to find the melody for all those nursery rhymes we learned as kids. You'll get those melodies in a short amount of time and will be able to figure out more complex ones later on.
On Monday I was teaching a student a song that she requested to learn. So I wrote up tablature for her. But she was struggling so much looking at the tablature that at one point I took the tab away and forced her to look at the fretboard. She protested that she can only play with tablature. But the problem was that although she knew the melody, she was getting distracted by all the information on the tab. When I forced her to stop thinking about fret numbers and note duration and just to play the song she had in her head, she was able to learn it much faster. In this case the tab was a hindrance to her learning the song. But even when that's not the case, using tab does not aid in the development of our ability to play by ear and may even sabotage it by forcing us to look at the music instead of our instrument.

The woman across the street from us has a huge garden and no one to feed, so we get all hers.
(That must be how Elvis felt when he first got hooked on liquid methamphetamine.) I brought the rest home for my wife, who had a similar experience.
, but the music plays on.