Memorizing Tunes

One of the hallmarks of traditional Irish music is the way it has been taught.  If you saw the movie "Boys and Girl From County Clare" (known as "Boys From County Clare" outside of the US), it starts with several boys learning tunes bar by bar from their teacher.  This has almost always been the way I have been taught a tune, bar by bar, and it is the way I like the least.
One of the cardinal memes of any folk music has been that you have to listen to learn the music.  Not only do you have to have the tune, but you have to have the stylistic features and the variance that goes along with the particular style of music. The meme goes on to say that you have to be able to sing the tune before you can play it and with this I agree hardily. It also depends on the instrument you play
In bluegrass, for instance,  Bill Monroe tended to be impressionistic about the notes of the tune while his fiddler, Kenny Baker, played every note.  In Irish traditional music (ITM) the tunes are played in ensemble in sessions (which are the most common setting) requiring most of the session to have the same variation of the tune in their heads.  Because there is so much noise (both actual and technical, i.e. minor variations) in a large group, any changes in the tune can go unnoticed unless you have a very loud instrument, like a banjo. But even then each of the instruments will have a different take on the tune.
As a result, for most people - especially at the beginner and intermediate level - learning a tune note for note makes a lot of sense.  Because the teacher is usually a master level player, the stylistic aspect of the tune is implicit which accounts for why we have regional styles.  There is a fairly broad stylistic range in any folk/aural music, but for the most part you can tell from whence it comes if you know the music at all.  It does make a difference on how you learn those notes, however.
By learning note for note and then practicing the passages and returning to the teacher, most students (at least the ones who practice) learn to play the tunes.  Later on, when they have developed a style, they can add variations or absorb other ideas about the tune.
For intermediates there is somewhat of a dilemma in that they are not only trying to learn tunes, but they want technical tips as well.  If you have a consistent teacher at this level, these tips come explicitly and implicitly as you observe your teacher/model and ask questions.  In workshop environments this is often difficult for the teacher unless all the students are at a similar level. 
But there is some value in beginners attending advanced classes.  Seamus Connolly once told me (and 150 others) at the second O'Flaherty Retreat in Texas that no matter what the level of skill, you always learn from a master, even if by osmosis and even if you don't know what you learned.  Music is not just notes, it is emotional, right brain and fun in addition to being the notes and left brain in the beginning.
This of course is not the main theme of my column, learning efficiency is.
There have been a lot of studies on how musicians tend to memorize pieces.  Most of these studies have been done with classical players who are learning to be professionals in their field.  In the 30s and 40s two methods were observed, Segmented and Holistic.  In the Segmented method a student would learn a passage, play it until it was right and then move on to the next passage.   In the Holistic style users played the entire piece through and then went back and worked on it until they were satisfied that it was correct repairing minor flaws as they came up. Interestingly the studies on which was more efficient were mixed and it appeared that both methods were just as efficient. 
In the 90s studies were done which showed that there were more ways to skin this particular cat than the two mentioned above and also that expert level musicians would vary the segment size of serial learning according to the formal structure of the piece or according to the difficulty of the passage.  Many of these segments were musically meaningful while others were not.  Apparently these inconsistencies accounted for the mixed results of learning the whole vs parts in prior studies.
In addition it was also observed that musicians used more subtle strategies to learn a piece including the Serial strategy in which a student would play a piece until a mistake appeared and then they would return to the beginning and start over.  In the Additive method the musician would memorize a segment and then systematically expand that segment until the entire piece was learned.  This differed from the Segmented method in that a prior learned segment was incorporated into the cycle instead of being set aside and then put together in the end. 
The Holistic and Additive strategies had the advantage of including all of the piece in the practice regimen.  The Serial technique includes all of the piece too, but it stops when a mistake occurs and there is a break in the continuity of learning the piece as a musical whole.
A study in 2002 showed that the Holistic and Additive methods were more efficient - in other words they learned the music a lot faster than the proponents of the other two methods.
A question still remained:  how well did they retain the music after learning it the first time?
The author of the 2002 paper, Jennifer Mishra of the University of Houston, decided to do an experiment to see how well each method worked for long term memory of a 16 bar exercise.  She took music education students and divided them into four groups each using one of the techniques mentioned above.  The results for efficiency mirrored her 2002 paper, the Serial and Segmented strategy uses took longer to learn the piece while the Holistic method users learned the fastest with the Additive method behind (by statistical analysis) but well ahead of the others.
The long term memory results were a little different, they all seemed to retain the passage a short time afterwards but the Serial method seemed to engender more errors.
When these students were asked how they memorized music, a large number (44%) reported that they used no system that they could discern.  Somehow they managed to learn a piece by muddling through although I suspect that they had a method but they didn't know what they were doing - a common thing among experts of all kinds.
So, according the the research, teaching bar by bar is the least efficient way to learn.  In Ireland and elsewhere where your teacher is always in the picture over a long period of time, this is not as much of a problem.  But in workshop situations it is.  I can only give anecdotes, but they are consistent.  In every class in which  the tunes were taught bar by bar people tend to drop out of the action one at a time and there is a particular problem of being able to accurately remember the first part of a tune even if it was solidly learned fifteen minutes before.  Most of this reflects either the level of the student or the learning style at which they excel (and possibly a talent for learning this way.) One thing I always hated was that the passages were not musically meaningful and that until I heard the piece played I didn't get the context.
I find that I learn a tune a lot better if I can sing it first and have it in my head relaxed and especially when it becomes hard to get out of my head.  I'll hear the tune a few times, attempt to play it, listen some more and then pick up on the subtle differences between my ear and the tune itself.  Rinse and Repeat.   Often it will take me weeks to learn a tune well but with tunes I really like it may only take an hour.
I'll often use the Additive strategy when I have a particularly hard piece to learn and will devote time in practice to learn a hard passage (although this is more a practice issue, I usually know the tune by then, I just can't play it.)
Things may be different for you.  It is clear that there is a wide variation in the ways that people learn things and there is no reason to think that memorizing a tune is any different.  The traditional way of learning (Segmented) works well in the context of regular classes and good motivation.  For those of us who don't have a teacher to show us how the tune goes, a combination of a recording/youtube and constant exposure to the whole tune makes more sense.

Here is a video of me playing Home Ruler and Kitty's Wedding, a set of hornpipes that were taught to me by Ken Fleming of the O'Flaherty Retreat.  Ken used an Additive method of teaching and he picked great tunes - Thanks Ken!