For those that struggle with learning music by ear…
First, don’t get discouraged. All skills take time, and learning how to play music by ear is one of the most rewarding skills you’ll learn.
The most important thing, of course, is training your ear. I’m not quite sure if "tone deafness" is something that a person can get past, but there are 3 skills that say you somewhat have a trained ear.
Staying on pitch
Noticing when you’re wrong
The next most important thing is how well you know your instrument. (Example, It may take a couple of minutes to learn how to play the melody of a tune on piano, and maybe take a couple days to memorize it, if it’s a fresh tune, because i’ve played piano for 13 years. But for that same tune, if i memorized it in my head first, it would take me days to learn on fiddle, and weeks before my fingers memorized it, and months before i began playing it well.) It’s healthy to get to know the structure of your instrument. This would be learning the scales and modes.
The third most important thing would be how well you know the genre of music you’re trying to play(but how well you know your instrument could help make this less significant) Familiarity with Scales, Cadences, Motifs, Arpeggios, and Transitions all help when learning a specific genre by ear.
The fourth most important thing would be how well you know the tune you’re trying to learn. A memorized tune is easier to learn than a fresh one.
The first skill you want, is to be able to recognize key signatures. This way you know the positions you’ll be playing in. 1 note can tell you what the key signature is, the other 6 notes just confirm it.(this is harder with modes)
The next thing is recognizing melodic and harmonic patterns(harmonic patterns being less important when playing ITM.) The thing about ITM is that is has very very distinct patterns, and all of the patterns are melodic.
The things that influence the difficulty of learning a tune by ear are Position,(how familiar you are with the key it’s played in, and how difficult the key is for that instrument) Tempo, Simplicity of Patterns, and Consistency of patterns.
A faster tune is a lot harder to learn than a slower tune. The longer you have to listen to one note, the more time you have to find it on your instrument. One skill to work on here, is what i call the "One note at a time technique". This is applied when a pattern goes by too fast for you to notice the notes that are in the pattern. This is done by holding the first note you hear, in your head, and then matching it on your instrument. Then you learn the rest of the pattern in sequence. This is the most tedious and frustrating technique i’ve learned, but sometimes it’s the only way. The more familiar you get with melodic patterns, the less you have to apply this technique.
For simplicity and consistency of patterns, examples that i’ve learned from are:
Britches Full of Stitches and A Kerry Polka(Peg Ryan’s), having the easiest, most consistent pattern. The Burnt Old Man, is a little more difficult, but still not difficult in itself because it also has repetetive patterns. The Boys of Malin has consistent patterns but they are longer, making them more complicated, and slightly harder to memorize
The two most helpful skills to develop are, Perfect Pitch, and relative pitch. Learning by ear, in it’s simplest sense, is playing a matching game. Matching the hertz that you hear, to the hertz coming outof your instrument. When you have Perfect Pitch, you hear a pitch and instantly know what it is. The closer you get to Perfect Pitch, the better guesser you are, the less time you spend making and attempting to correct mistakes.
There are many many skills involved when learning music by ear, and most of them are things that happen in your head. (which is why you can’t learn how to play by ear when watching someone else learn by ear. Also why it’s hard to teach others how to learn by ear) But like most things, these skills take time to learn and master.
I hope this helps