Let's begin by first explaining the process of learning by ear:
Suppose you wanted to learn how to play a simple nursery rhyme like "London Bridge is Falling Down" or "Three Blind Mice."
One would more than likely not seek out the TAB or sheet music to accomplish this. Why?
Most people have these nursery rhymes in their memory so well they can hum or sing them. The process would consist of humming/singing the tune and then finding it on the instrument of choice through trial and error. The better the hand-to-ear connection, the faster one can find it with less errors.
The process of playing by ear is demonstrated by this skill-to be able to hum/sing something in ones musical mind and be able to find it through your instrument quickly. Eventually the goal is to to find a melody heard on record or in one's musical mind immediately without error.
What steps can one take to obtain this ability?
One can take nursery rhymes and play them starting on different notes. Take "London Bridge" for example and start on an A note, then try it starting on a C note. Play the melody through various keys.
At first, you might be surprised your hand-to-ear connection is slow. However, with enough of this type of work it will speed up.
Once you can do one nursery rhyme try another simple tune. Some to consider
"Mary had a little lamb"
"Three Blind Mice"
"Twinkle Twinkle Little Star"
Once again, try each one starting on different notes, different octaves, different positions, etc.
Once you can do this fairly well, the next step is to try to transcribe something from a record. This can include Chord Changes, Solos, rhythms, Backup, etc. Start with something well within your grasp. We want this to be a positive experience and not a discouraging one. If you start with something too complicated, it will be too tedious.
How do you properly Transcribe?
1)Put on the recording you wish to transcribe and listen to it over and over
2)Listen to the point that you can hum/sing the part you wish to learn. Yes, you want to practice singing/humming the part along with the record without your instrument.
3)Go to your instrument and try to find the melody/lick of interest without listening to the recording. Do it from aural memory, by singing or humming it and trying to find what you hum on the instrument.
4)If all else fails play the recording and try to find it, piece by piece.
5)If this still doesn't work then Slow it down using software such as Transkribe or The Amazing Slowdowner.
These processes will have you on your way to a better ear.
It is of great err when people make statements about how only a elite/select group of people can learn to play by ear. All but the tone deaf can learn this skill. Granted, some will find it easier than others; but if your "want to" is there you can learn to play by ear.
Now, let's discuss written music.
Written Music also has it's advantages and should be a part of the musicians skills.
If you wanted to learn Bach's Cello Suites, would you want to learn them by ear? One could, but I'd venture to say you'd be spending unnecessary time. There are thousands of other classical musicians that have learned Bach via sheet music and it has not affected their performance. However, it's not as simple as reading the page. They deeply think about dynamics, articulation, fingerings, etc. They have also studied the recordings of those that have went before them with the same piece.
Written Music allows one to learn a song quickly with good sight reading skills. It also enables one to learn chord changes to tunes that our ears can't quite hear yet. Yes, more than likely in your journey as a musician you will want to learn something you can't figure out by ear.
My personal opinion is that written music should be used in conjunction with recordings of the music whenever possible. Written Music can denote many things but it can't explain everything.
Articulation and exact accents are difficult to indicate in music. There is a whole level of EXPRESSION that won't ever translate into symbols on a page.
For those of you that want to improvise, playing only from written music won't help you acquire this skill. For example, a classical musician that's capable of playing Paganini's Caprices isn't equipped with the skills to improvise over "Autumn Leaves." by default. Good sight reading skills and technique don't lead to amazing improvisations. Only training your ear will lead to that skill.
In order to improvise you have to be able to hear the chord changes. One also has to be able play the form without getting lost and place the melody and phrases correctly in time.
In summary, learning by Ear and written music should complement one another. They both leave one with specific skills sets, both of which are important. Train your ear, learn to read music, and study music theory. They will most definitely keep you on the path to becoming a better musician.
MORE TO FOLLOW WHEN I GET TIME.