The Leitner System - a randomization strategy for efficient and effective practice

When I first came back to clarinet I practiced a lot, but I wasn't making progress. I had too much to master each week, and not enough time to work on it. Then I realized that I was practicing too much, without prioritizing what I didn't know.  Enter the concept of spaced repetition and the Leitner System.

The Leitner System is a well-known and very effective method of using flashcards. It's a form of spaced repetition that help you study the cards you don't know more often than the cards you already know well.  Here's a quick overview of the classic Leitner System

This system is intended for memorizing and drilling facts -- in a quick, question and answer format. It's not suitable for practicing complex, expressive pieces, but it can work well for short technical exercises like scales and arpeggios. I use it to work on exercises for my weekly lesson. In that context, weekly and bi-weekly practice don't apply, so I modified the system to randomly choose what to practice next. In real life I do it on the computer, but here is an approximate manual equivalent.

You need 5 boxes, a pair of dice, and a set of cards, like those print-at-home business card sets for inkjet printers. When starting a new batch of exercises (a "deck" of cards), play through each exercise to establish the fastest tempo at which you can play it. Accuracy trumps speed though. Better to play slow and correct than fast and wrong. Write the exercise name and tempo on a card, and put the card in Box 1. Don't spend more than 2 minutes on any one exercise. If you have 25 exercises and spend 2 minutes on each, that's roughly an hour of practice time.

You start with the whole deck in Box 1. Here's how subsequent practice sessions work. The idea is to practice for a fixed amount of time, focusing on the more difficult items, and randomizing them so you are forced to react to unfamiliar situations. Think in terms of two 30-minute sessions per day, one in the morning and one in the evening.
  1.  Roll the dice. If you roll between 1 and 6, choose a card from Box 1, 7-9 Box 2, 10-11 Box 3, 12 Box 4. If there aren't any cards in that box, choose a card from the next lower box
  2.  Play through the item a couple of times, starting at the tempo on the card. If it's comfortable, you might crank the tempo up a notch, and write the new tempo on the card. But don't spend too much time on any one item. 3 minutes is a long time in this context. If it's really easy, don't dwell on it -- save your time for material you don't know.
  3.  Would you be OK with that performance in your lesson? If it's unacceptable, move the card back to Box 1. Otherwise move the card to the next higher box. Or, if it seemed really easy, you might bump it up two boxes.
  4. Is Box 1 empty? If so, move the empty box 1 to the end, so it becomes Box 5. What used to be Box 2 is now, becomes Box 1, etc. etc.
  5.  Is your practice time up? If so, stop the session. Otherwise, roll the dice, rinse and repeat.
Note that you may wind up playing the difficult items several times in a session, interleaved with the other items. That's by design.

Ankimono is an app (not intended for music practice) that will do something like this, though it won't handle keeping track of tempo changes. There is a web implementation at,  an Android version  called AnkiDroid on Google Play, and a iOS version called AnkiApp on the App Store.