As a teacher, I’ve often pondered this question, concluding that there are varying answers which depend on the advancement and motivation of individual students. Certainly no fixed formula addresses the length of time a pupil needs to fully realize his potential when practicing a given composition.
By way of example, I have an adult student, who pursued piano as a child into her teenage years, and had a long hiatus from lessons until mid-life when she resumed studies. I had observed that she was very motivated to learn the Classical repertoire because she had grown up with a strong cultural exposure to music of this genre, and she was willing to develop a strong foundation based on a regimen of scales, arpeggios, and ground up learning of minuets, to sonatinas, to fully developed sonatas. The commitment was strong, and the time allotted for practicing was substantial and consistent.
But these particular circumstances would not be common to every pupil taking lessons.
In this woman’s situation, within three years she had the potential to play Beethoven’s “Fur Elise” and the Chopin Waltz in A minor, though she realized that she would probably be practicing these pieces in layers from the ground up for a significant time if she desired to reach a level of proficiency that she desired.
That meant being attentive to fingering, phrasing, separate hand practice, dynamics, harmonic analysis, etc. without feeling that she would have to reach certain milestones at a fixed deadline. There were no value judgments attached to learning curves.
Where a student commits to this paradigm of study, the journey is the reward instead of a formulated end game. Whether a student needs six to eight months to develop the skills to play an advanced work, is not the issue, unless he makes it so.
In most cases, a teacher and student can come to a consensus about what variation in repertoire is best recommended to hold the pupil’s interest and keep him enthusiastic about learning.
The Chopin Waltz had been the centerpiece of the adult student’s practicing until it reached a plateau, and was then joined by Beethoven’s “Fur Elise,” which benefited from the time, and depth of study applied to the Chopin. The second piece also added a variety of musical styles that enriched and advanced the student’s knowledge of the piano on technical and musical levels. Each piece had its own learning landscape and complemented the other.
In a collaborative student/teacher environment, the “feel” for the right time to move from one piece to another presents naturally without stress or strain. Sometimes adding a composition (popular or otherwise) invigorates the student and gives him an enlarged perspective about his whole learning experience.
Where younger students, with less time to practice, grow tired of even short pieces far too early during their exposure to them, a discussion of goals with parents and pupils is probably needed.
Due to the impatience of youth, many youngsters would like a more espresso passage through many pieces, skimming the surface, and moving on to the next. Sadly, this type of learning can breed discouragement quicker than it takes to discard one piece and replace it with another. Before long, the student has lost interest in taking lessons entirely.
Even if a pupil insists that a particular piece will energize him, at least at the outset, if practicing habits and commitment to working out a piece in a step-wise way are unappealing, then whatever flavor of the week composition is assigned, it will not stand the test of time to develop to a level of proficiency where the student feels happy about the outcome.
Back to the same question about staying with one piece or another, and for how long?
For me as a teacher, I believe that when the student has done his best within his potential and skill level to take the necessary steps that will allow a piece to ripen–to be played smoothly, with an attached level of confidence that gives him satisfaction –then it can be rested, and revisited at a later time.
And this brings up decisions that are made by teachers where it concerns choice of repertoire, and whether a particular piece can be so far from technical reach that it will be a guaranteed journey of frustration.
For many students a combination of pieces that are challenging enough to be practicing motivators, alongside those that can be mastered more readily and used perhaps as sight-reading adventures to develop those particular skills, might offer a balanced musical diet.
Striking this desired balance, presenting the student with compositions that stimulate growth and require a consistent, long-term relationship, beside diversified repertoire that may be more readily assimilated, should keep the student moving along while simultaneously exploring musical depths.
In short, there are no easy answers associated with the amount of time a student spends with a particular piece. The best approach, in my opinion, is mixing things up, and having an open dialog with the student and parents about progress, goals and what’s realistic given the pupil’s schedule. Collaboration, above all, heads off any authoritarian time lines that stratify learning and send students out the door before they have stayed around long enough to appreciate the joy of music-making.