The traditional honkyoku-pieces of the Komusō-Shakuhachi are transmitted in direct encounter between teacher and student. In the old days the teacher would have known all his pieces by heart, he would not have used any notation when showing how to play. The student then played what he had heard and took notes. Here is what Nishimura Kokū 西村虚空 (1915-2002) writes about his Shakuhachi lessons with Tani Kyōchiku 谷狂竹 (1882-1950) in 1943:
I took lessons three times a week, but for half a year the master made play only Ro - that one single note. And whenever my lesson on the single tone Ro was finished, he would play the piece Ajikan for me. And thus, before I even noticed it, Ajikan had become deeply engraved into my heart, and after half a year I was able to hum along. After half a year of taking lessons on the tone Ro, to my great surprise he told me: "Now I can certify that you have learned everything!" Only now do I understand what he meant at that time. One year after I had come to Tōkyō I had played Ro for six month and for another half year I had learned without any notation. He would play a certain phrase and I would repeat that part, and day by day the amount of what I could play increased. But at the same time I had more and more problems to to remember what I had learned. I had become able to play the pieces Yamato-chōshi, Kyō-chōshi, Kokū and Ajikan by heart. Then finally, when I was about to being transferred to Itō Hospital he said to me: "Humans sometimes forget things, take those scores, copy them to take them with you," that's when I saw shakuhachi notation for the first time. (Own translation from: Inagaki Ihaku (ed.), Komusō Tani Kyōchiku, Komusō-kenkyū-kai 1986; p. 164)
Until the beginning of the 20th Century when the modern Komusō revival started with Higuchi Taizan 樋口対山 (1856-1914), the Komusō played only the pieces of their local traditions i.e. the temples they were affiliated with. The number of pieces was relatively small. But Higuchi Taizan collected a great number of honkyoku from all over Japan and he created a major part of the repertoire that is now played. The number of pieces played in different groups in Japan is difficult to estimate, but the two traditions I have studied thoroughly play around 50 pieces from different local traditions as their core repertoire.
Such a relatively great number of pieces is difficult to transmit, memorise and remember without any notation, thus a simple form of notation using the Japanese Katakana characters ro ロ, tsu ツ, re レ, chi チ etc. has now become widely used (but there do exist other notation-systems). Those scores serve merely as an aid for not-forgetting, and not more than the general finger-positions are recorded there. They have no symbols for rhythm, the exact pitch, volume and all the other details you can find in Western musical scores (and in modern Shakuhachi scores as well). It is therefore impossible - even for an experienced player - to play a honkyoku-piece only by looking at the notation, the information is just not sufficient.
In order to get a reliable idea of how a new piece is played you need someone to demonstrate it for you and that is the role of the teacher. You might think that listening to a recording while looking at the notation might be sufficient, but in fact it is not. Small but important details are not written down and one will normally miss those when listening. Furthermore, the same tone can be played with different finger-positions and the same symbol in the notation can have different meanings depending on its context. That sounds like an slightly odd way of transmitting the core of the tradition and maybe it is. Why that system is deliberately not changed into something more "effective", is an important question, because it would be quite easy to do so.
Learning from a teacher
A cynical (and very modern) approach to the problem would be, that the Shakuhachi-players simply do not want outsiders to know how their honkyoku are played. But there might be a more serious reason that has to do with the religious or spiritual side of the Komusō-Shakuhachi. Zen is usually counted among the so called "exoteric" traditions of Buddhism (jap. kenkyō or kengyō 顕教), that is to say that the Buddhist scriptures of those traditions are believed to contain and transmit everything there is to know. But on the other hand Zen also stresses the necessity to study with a qualified teacher without whom it is very difficult to grasp the real / existential meaning of those texts. The explicit "esoteric" forms of Buddhism (jap. mikkyō 密教) hold that the inner meaning of the Buddhist teachings can generally only transmitted by a teacher to his or her disciples in certain initiatory ceremonies for which quite some preparation is required.
The "spiritual" aspect of playing the Komusō-Shakuhachi (one could also call it the playing of the Shakuhachi as a means for self-cultivation / or rather the cultivation of self-less-ness?) takes place when you confront the teacher and present your way of playing to him. That will reveal, among many other things, your way of breathing, your pride or apprehension etc. And the teacher will also reveal his present situation to you completely. How he corrects you, challenges you and how you ask your questions in words or without words, this is the place where the living flesh of practice is attached to the bones of mere traditional playing-formalities. That is not always nice and instructional as you would expect some musical lesson to be, but can be a rather fierce situation. And at times you are reminded that the Komusō have quite something in common with the Japanese warrior class. There may be times when you need to become fearless like a samurai to meet your teacher.
About online lessons
In our day and age there are many Shakuhachi players teaching all over the world and particularly the jinashi-shakuhachi, here referred to as Komusō-Shakuhachi, has many friends in the West. This kind of Shakuhachi is even more popular abroad than it is in Japan, what is not surprising as many Western players are looking for the distinct "Japanese" or soft and natural sound that it produces. (Many Japanese, it seems to me, prefer flutes with which Western music can also played easily.) Therefore it might be possible for many prospective players to find a teacher living not too far away and to meet him or her for personal instruction.
But there are still blank spaces on the map, and if you happen to live far away from the bigger cities where the chances to find a teacher are relatively good, you might think of taking online lessons. That is now a technology we use every day and connecting live around the globe doesn't even surprise us any longer. I have also done quite some online-teaching and - as it cannot always be avoided to connect using such technology - still do so.
But I have come across a number of difficulties that seem to be unavoidable when teaching online. The first trivial but real problem are the time-zones. The time convenient for the student might be in the middle of the night where the teacher lives or the other way around. Unless both of you are living alone without neighbours and families that can cause some obvious problems.
Another and more specific problem is the fact, that student and teacher cannot play unisono. There is always a small time gap and besides this I find it impossible to hear what my student is playing when the tone of my own Shakuhachi is also there. But playing together is the most effective and direct way to convey the character of the honkyoku.
The teacher shows you how to play the pieces, but that is not all. If you share physically the same space with him - or any other person for that matter - you will experience more that just his tone. How does he hold his teacup? How does he manage the weather? How does he react to mosquitoes? How does the cat react to him? And simply how does his presence feel to you? That might be far-fetched but if you have ever been in the presence of a charismatic teacher (with all the problems the use of such a term brings with it), maybe you can understand what I am referring to.