Sunday, June 24, 2007

"Chunking" Bach's Invention in C major

I have taught Bach’s C major Invention (in 2 parts) to quite a few students over the last few years. This short piece is one of the big milestones that all accomplished intermediate pianists need to conquer in order to prepare themselves for the technical demands of the advanced repertoire. I think that it serves as a great example for teaching about “chunking”; that is, breaking a piece into small parts in order to make the most of practice. This post will be devoted to explaining the utility of chunking when it comes time for a student to learn this piece. (Download a free copy of this public-domain work here.)

Now it must be said that some of my talented early-intermediate to intermediate piano students did not need to divide music into smaller parts very often. They may have been good enough to avoid it for the first three or four years of study. When a student like this did need to divide the music, it would suffice to either practice in two parts (for the simple binary compositions) or to practice in three parts (you guessed it, for the ternary compositions). But without exception in my experience, when a student gets to the Bach inventions it becomes absolutely necessary to go beyond chunking and divide the piece into much tinier segments. To practice this invention even in three parts can be completely overwhelming for the less experienced intermediate student. In fact, when I teach this piece I usually divide it into about ten to twelve segments!

Why does it become necessary to do this? The complexity and independence of the two lines is what makes the work difficult to learn for pianists who only know the easier minuets and marches by Bach. Imitative counterpoint like this takes effort to coordinate. The renowned pianist Walter Gieseking wrote the following in his practice advice for the C major invention:

“It is not advisable to play the whole invention straight through, when studying. In fact, this should be forbidden. Only small parts should be practiced at a time; and these should be repeated over and over again, so that irregularities and unevennesses may be immediately corrected. It is much more difficult, if not impossible, to do this when longer parts are played.” (1)
Gieseking knew what he was talking about and if it was good enough for him, it’s good enough for me. Simply put, students will not succeed at mastering this piece unless they do two very specific and important things:

a) Figure out some way of dividing the music into small parts, and
b) Resolve to learn each part through repetitive practice of just that part.

Here’s a game plan for breaking up this piece. Refer to your score. (Again, you can download the score here.)

Let’s divide the piece into three large CHUNKS first.

A) Measure 1 to the downbeat of measure 7 (notice the cadence in G at m. 7)
B) Measure 7 to the downbeat of measure 15 (ends with cadence in a minor)
C) Measure 15 to measure 22. (end of the piece features a final cadence in C)

To practice the entire piece effectively during the first few weeks, the student should map out a plan to practice each chunk on separate days in a clear cycle. This will help avoid the common problem of crafting a performance with a great-sounding beginning, an ok-sounding middle, and a terrible-sounding ending. For example, the student could try the following:

Monday: Chunk A
Tuesday: Chunk B
Wednesday: Chunk C
Thursday: A
Friday: B
Saturday: C
Sunday: A (or day off)

…And so on. Once that has been figured, it then becomes necessary to organize the practice of the specific chunk on each day. Let’s say I am just starting out on this piece on Monday so I need to practice Chunk A according to my weekly plan. I’m going to devote twenty minutes each day to this piece. We're going to break the chunk into even smaller segments. Here’s what we can do:

1) Practice each hand separately and SLOWLY from m. 1 – 7. Write in good fingering and leave out the ornaments (like the mordents and trills) for now. ( 5-7 minutes)

2) Divide Chunk A into three segments (m. 1-3, 3-5, 5-7). Always overlap your practice segments to the downbeat of the next measure so that you don’t have any practice “gaps”.

3) Practice the first segment hands together slowly. If you make mistakes and hesitate a lot, you are either going too fast or you need to divide the segment into one-measure “segmentites”. (I just made that word up…) You can also review the segment hands apart if you need it. (2-3 minutes)

4) Once you can do the segment cleanly without note, rhythm, or fingering mistakes, try to repeat the segment perfectly five times. Remember, keep it SLOW for now! (3-4 minutes)

5) With the time left over, try to do segment 2 in the same manner as in (3) and (4) above. (5-6 minutes)

And there’s practice day one. Now of course you have noticed that we didn’t make it to segment 3. That’s ok; just be sure to hit segment 3 the next time you practice Chunk A, which would be in three days. You then try the same process with Chunk B the next day, Chunk C the following day, etc. Eventually, you will be able to tackle all the segments in a chunk easily in one twenty-minute session.

The next practice step is to string segments together until you can play the whole chunk well. Let’s say it’s week two and you’re back to Chunk A. Here’s how you use your time:

1) You can play segments 1 and 2 perfectly, but segment 3 is a little messy. Practice segments 1 and 2 separately (with a break in between). (3 minutes)

2) String together segments 1 and 2 and play through without stopping. Try to do this perfectly five times. You might need to slow down. (5 minutes)

3) Practice segment 3 alone until it’s better. Let’s say it improves to perfection. (5 minutes)

4) Now what should you do? You should string together segments 2 and 3 first. Don’t try 1-2-3 yet! Baby-step into playing the whole chunk by doing some overlapped 2-segment practice. (3 minutes)

5) The last thing you should try is to play the entire chunk through a few times. If all goes well, you are on your way to getting the piece together. (2-3 minutes)

Soon it will be time to start stringing the big chunks together. You’ll discover that as you progress it will take less and less time to play through each chunk because it will be mastered perfectly if you follow this plan. Here’s what week 4 might look like at the start:

Monday: Chunk A, Chunk B separately. A-B nonstop.
Tuesday: B, C. B-C nonstop.
Wednesday: A, B, C. A-B-C nonstop.

By Wednesday, you’re playing through the whole piece. Since you practiced each chunk equally throughout the process, the piece should sound consistently good all the way through. If you follow a method like this with discipline and care, you just cannot go wrong. It will seem that the piece will learn itself. You would be doing yourself a huge favor if you also memorized each chunk as you mastered it.

If at anytime in the process you get stuck and don’t improve, you can always go back a step and re-do your segments. As soon as you get to a “purple patch”, you go back to segmenting until it gets better. Then you move ahead in the process.

Right now, you’ve read this far and are most likely exasperated at how detailed this practice ethic can get. You might also suspect that there will be hurdles along the way, that some chunks and segments will come easier than others, and that this situation might be too “idealized” to work practically. Well, let me say that of course it won’t be easy, but this method is the only way to learn a difficult piece to the point of mastery in the shortest time possible. This is how the pros do it. For me, this is exactly how I have to learn a piece of music if I am to play something on a professional level in a short amount of time. Chunking works wonders, and the best part (no pun intended) is that you will learn the whole piece much quicker than if you always start at the beginning of a piece when you practice.

Yes, it takes patience, focus, and careful planning. But the students of mine who followed this kind of practice plan always got to a high performance level in the end. They felt great about their solid accomplishment in this Invention and learned to apply the process to other difficult pieces. A Bach invention today, maybe a Rachmaninoff concerto tomorrow?


(1) Walter Gieseking and Karl Leimer, The Shortest Way to Pianistic Perfection, in Piano Technique(same authors) (New York: Dover 1972), 26.


gottagopractice said...

Hi Joshua,
Thanks for this (for me) timely post. I have studied piano for two years, with a primary goal of using the keyboard skills and applied theory to improve my 'cello playing, but a secondary goal of being able to play Bach two-part inventions, which I love. I'm also one of those students who is stuck between pieces I can learn at one go (or can already almost play, if you will) and those that require chunking to master. I think I have a fear that I won't remember a chunk long enough to practice it in cycle. I have two questions, if you have a few moments.

1) Is this C MAJ invention the first two-part invention you teach?

2) One of my psychological impedements to slowing down and focusing on a small section for the time it takes is that each week my teacher asks me to play the whole piece, so I have a strong drive to play the whole thing. I *know* that is counterproductive. I was wondering what you ask your students to play in the lesson while they are in the process of working slowly through the chunks.

Thanks for blogging.

Joshua Nemith said...

Hi Gottago; answers below to your two questions.

1) I do usually start with this invention when introducing the genre to a student, but I've been know to start with the F major (No. 8). All of the other ones are more difficult, IMO.

2) If a student of mine is in the "chunking" process, I'll usually just ask for the chunks and not the whole piece. You might ask your teacher if you can do this at the lesson first, then try the whole piece. Secondly, I understand the fear with cycling and remembrance, which usually means the whole piece is a little overwhelming for you. Well, that's fine! If it's two pages long, just treat the first page as a complete piece in and of itself for now. Master that, and you can then go on to the "next piece". Doing it that way might make it easier to cycle the material more often. It's certainly better than giving up. Hope this is at least a little helpful to you!

PS Just FYI I usually do not get to the inventions until a student has had about four to six years of lessons. But don't be discouraged: Have you done the marches, minuets, short preludes, and musettes of Bach yet? I'd start with those if you haven't done some of them already. They are easier than the inventions but are musically sophisticated enough to satisfy an itch for the music of Bach. Ask your teacher first, but I could also suggest some pieces if you want.

gottagopractice said...

Thanks for your detailed response. I was so inspired by your post that I have just finished my fourth practice day working according to your plan. Except that it takes me about an hour on each segment, not 20 minutes! If you have a few spare minutes jump over to my blog and listen to short recordings of the last 3 days' results. Please let me know if you think I am in over my head! And I would definitely be interested in recommendations on where to find other pieces, especially the preludes you mentioned. I am in a 2 month hiatus in my group lessons.

Joshua Nemith said...

Hi gottago. I left a comment on your blog about your practice samples. I will do a separate post on "training wheel" Bach pieces in a few days.

gottagopractice said...

Thank you so much! I am looking forward to your next Bach post - though I also expect that this is enough to keep me busy this month <g>.

robert said...


This is a wonderful posting. I'd thought of doing something along these lines in my piano blog -- but how could I improve on perfection?

It will be great for my students; I'm in the process of geting into teaching. It's great for me to be reminded of these things; I'm starting JSB's C minor Toccata.



Joshua Nemith said...

Thanks for the compliments, Robert. Best wishes on your teaching, blogging, and learning Bach's toccata.

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