So how slow is slow?
Ultimately, though, you are the only person who can answer that question.
In the paper, It’s Not How Much; It’s How, Characteristics of Practice Behavior and Retention of Performance Skills, Robert Duke, Amy Simmons, and Carla Davis Cash observed 17 piano students as they practiced a difficult, three-measure passage and then ranked the students when they performed the piece on the following day.
The students who ranked the highest during their performances, used the following techniques when they practiced:
- Errors were preempted by stopping in anticipation of mistakes.
- Errors were addressed immediately when they appeared.
- The precise location and source of each error was identified accurately, rehearsed, and corrected.
- Tempo of individual performance trials was varied systematically; logically understandable changes in tempo occurred between trials (slowed down enough; didn’t speed up too much).
- Target passages were repeated until the error was corrected and the passage was stabilized, as evidenced by the error’s absence in subsequent trials.
The authors noted “the most effective way that the participants corrected errors was by making judicious changes in performance speed that facilitated the maintenance of accuracy following the correction of a given error.”
The phrase “judicious changes” is key. The authors did not observe that any of the top-ranked pianists practiced at a specific tempo; there was no target tempo for “slow.” Rather the top-ranked pianists emphasized eliminating errors. Practicing slowly was the primary mean to that end.
Perfect Practice makes Perfect Performance: We’ve all heard the cliché. Overused or not, clichés often contain a grain of truth which is why they have survived as phrases on our lexicon. The students in Duke, Simmons, and Davis’ study were all accomplished pianists. They knew their abilities, though. When they encountered phrases that they played incorrectly, they slowed down to a tempo at which they knew they could play the phrase correctly. An additional, and important, point to note is that the students focused on stabilizing problem phrases so that they would not occur again.
Another important finding in this study is that the students did not speed up too much when they brought the piece up to tempo. The students progressively worked their way up the tempo ladder. It is not just a question of playing slowly, it is important slowly engage the throttle. As pointed out in numerous Dojo U classes, playing slowly gives you more time to execute properly.
These are key points and they illustrate the fact that there is no absolute value for a slow tempo. Only you have the answer to the question “how slow is slow?” Understanding your own abilities, understanding how embellishments should be played, and understanding the appropriate tempo at which you can practice; when have an understanding of those three points, you can then answer the question, "how slow is slow?"