038 - The Secrets of Interleaved Practice: What We Can Learn From Cognitive Science


Resources Mentioned

*Disclosure: I get commissions for purchases made through links in this post.


In the last episode, Episode 37, we talked about playing your instrument for fun and why that is vital to your music career. Today, we're going to follow that up with a conversation about practicing.

If there's one thing we know it's that practicing is fundamental to developing skills as a musician. And as music teachers and educators, we're always looking for new ways to encourage and inspire our students to practice at home, whether that's singing, exploring rhythms, listening to music, or playing their instrument and following our home assignment sheet.

It may surprise you to hear me say that much of what we do when we practice is not really about music; it's about the brain and how we learn and process new information.

That's why today, I'm sharing some research from the wonderful world of cognitive science.


What Is Interleaved Practice?

I started thinking about this topic back in the summer at NCKP, the National Conference on Keyboard Pedagogy, when I attended a session on interleaved practice taught by Barbara Fast.

This is the first big idea that I want to share with you today.

If you're not familiar with the term, interleaving is an approach to learning and practice that involves mixing up the sequence of topics, skills, or strategies so they are woven together throughout a practice or study session.

In his book, How People Learn: The Surprising Truth About When, Where, and Why It Happens, Benedict Carey summarized, “Interleaving is, essentially, about preparing the brain for the unexpected.”

Interleaving is an approach to learning and practice that involves mixing up the sequence of topics, skills, or strategies so they are woven together throughout a practice or study session.
— Ashley Danyew

Blocked vs. Interleaved Practice

Think about the way you approach practicing (or the way you want your students to approach practicing)—even the way you write an assignment sheet for home practice. Most of us tend to organize things in blocks, right? Warm-ups and technical exercises, sight-reading, repertoire, theory, and creative assignments.

In blocked practice, we play through all of our scales before we go on to chord patterns. We do all of our sight-reading exercises before going on to our repertoire assignments. We rehearse everything in one piece before going on to the next.

Contrast this with interleaved practice, where you might play the scales that tie in with your first repertoire piece, then come back to scales later as they relate to another piece. Or perhaps you practice them with variations each time you come back to them. You may intersperse 1-2 sight-reading exercises between each repertoire piece instead of doing them all at once.

Benedict Carey explained, “Studies find that the brain picks up patterns more efficiently when presented with a mixed bag of related tasks than when it’s force-fed just one.”

So what does this look like in music practice?

Barbara Fast, who taught the seminar at NCKP this summer, recommends trying 4-, 8-, and 10-minute practice segments but only choosing one thing to interleave:

  • technique

  • drills

  • a new skill

  • time of day

  • practice strategies

  • odd/even phrases

Whatever you choose, focus on one new skill or concept and weave that throughout your practice session in small doses.

If you’re looking for more ideas, Gerald Klickstein, author of The Musician's Way and the companion site, musiciansway.com, wrote a post on interleaved practice (plus a few other strategies).


Constant vs. Varied Practice

The second big idea that I want to talk about today, and one Gerald also mentions in his post, is to create conditions of varied practice (vs. constant practice). 

Constant practice means practicing the same skill the same way day after day (repetition is key, right?). This is what we love about the blocked approach: structure, order, simplicity, and knowing what to expect (and all the Type A musicians said, "Amen!"). 

Varied practice, on the other hand, means practicing the same skill but in different ways: sometimes fast, sometimes slow; sometimes with alternate rhythms; sometimes under different conditions. Benedict Carey noted that "each alteration of the routine further enriches the skills being rehearsed, making them sharper and more accessible for a longer period of time.” In other words, continually finding new ways and conditions to practice, never getting too comfortable, and mixing it up so you never know what to expect. This helps engage the brain and deepen learning.

“It’s not that repetitive practice is bad. We all need a certain amount of it to become familiar with any new skill or material. But repetition creates a powerful illusion. Skills improve quickly and then plateau. By contrast, varied practice produces a slower apparent rate of improvement in each single practice session but a greater accumulation of skill and learning over time. In the long term, repeated practice on one skill slows us down.” - Benedict Carey, How We Learn

This is consistent with a study by Christine E. Carter and Jessica A. Grahn comparing the effects of blocked and interleaved practice schedules on advanced clarinet performance.

The authors discovered that "while the majority of participants found the interleaved practice schedule more useful than the blocked schedule, the majority still preferred the blocked schedule. This supports previous findings that blocked practice is often favored over more challenging training conditions because of increased feelings of fluency after repetition."

It makes sense, doesn't it?

The brain has to work harder in interleaved practice because every time you come back to something you worked on a few minutes ago, the brain has to retrieve that information again. This may result in weaker performance skills in the moment (because you can't rely on the power of repetition), but it builds stronger neural connections and pathways, which helps with retention.

Basically, interleaved practice may be better for long-term learning.


Why Is Interleaved Practice Better?

Let's pause here for a moment and discuss:

Are these approaches really that different? If we're honest, the varied approach feels a little scattered and disorganized. Aren't all those interruptions detrimental to focus and productivity? And when it comes to blocked vs. interleaved, is it really helpful to the learning process to switch tasks every 8 minutes?

I hear you. These are all valid questions.

Some of these research findings do seem to contradict things we thought we knew or understand about how the brain processes new information.

Here's one explanation from psychology professor Steven Pan: 

"[Interleaving may] improve the brain’s ability to tell apart, or discriminate, between concepts. With blocking, once you know what solution to use, or movement to execute, the hard part is over. With interleaving, each practice attempt is different from the last, so rote responses don’t work. Instead, your brain must continuously focus on searching for different solutions. That process can improve your ability to learn critical features of skills and concepts, which then better enables you to select and execute the correct response."


What We Can Learn From HIIT

This makes me think about HIIT (high intensity interval training) workouts, something I discovered during quarantine.

If you're not familiar, HIIT workouts are a sequence of short, high-intensity activities followed by short periods of active rest. It's cardio-focused with core and strength-training elements.

I realized when doing this research on interleaved practice, that that's one of the things I love about HIIT workouts.

It's not five sets of 30 jumping jacks followed by three sets of 15 burpees followed by two sets of 10 push-ups. It's usually 2-3 blocks, each with 3 high-intensity activities, 20-30 seconds each, followed by 10-15 seconds of rest. You usually do each block 2-3 times before moving on to the next one.

In total, you might do nine different exercises (2-3x each), but you interleave them not only to keep your brain active and engaged but to spike your heart rate and burn more calories in less time.

I know that seems like a random connection, but maybe it's a model we can use in practicing: interleaving activities but organizing them into the block structure we know and love.

Let's talk through an example of what this could look like:


Sample Interleaved Practice Routine for Music Students

Let's say you're working with a high school student to create a home practice plan. First, choose one element to interleave, as Barbara Fast suggests—maybe scales.

Then, plan out your practice blocks. For instance:

Block 1:

  • Scales - variation 1

  • Repertoire piece 1

  • Sight-reading

Block 2:

  • Repertoire piece 2

  • Scales - variation 2

  • Repertoire piece 3

Block 3:

  • Repertoire piece 4

  • Scales - variation 3

  • Pop-style piece

Repeat each block two times before moving on.

You could also add in quick change-of-pace activities in between blocks, like theory assignments, listening, or ear-training exercises.

Scale Variations

The scale variations could be things like fast and slow tempos or maybe you do different keys at different points in your practice session that day; maybe you practice right hand alone or left alone, maybe you practice with alternate rhythms; maybe you're practicing in a formula pattern where you're combining some contrary motion scales and some parallel scales.

You can decide with your student what would be the most effective practicing strategies to try, but make sure they have several different ways for how to practice their scales during the week.

Notice, too, how I mixed up the order of things within each block: So I didn't always start with scales followed by repertoire followed by something else. This helps keeps things fresh and interesting, keep your brain mentally engaged and active while you're practicing.


I’d love to hear your thoughts.

Do you see how a structure like this could be beneficial to long-term learning? That having your student practice their scales every day with three different variations could further enrich their understanding and development of this skill?

I'm really curious to hear if this is something you've ever tried before. If so, how do you organize your time? Do you like the blocked approach with one interleaved skill or concept?

Let me know if you decide to experiment with this structure in your own practicing or with your students. I'd love to hear how it goes!


Sources:

Carey, B. (2015). How We Learn: The Surprising Truth About When, Where, and Why It Happens. Random House Trade Paperback Edition: New York, NY.

Carter, C. E. & Grahn, J. A. (2016). Optimizing Music Learning: Exploring How Blocked and Interleaved Practice Schedules Affect Advanced Performance. Frontiers in Psychology. Retrieved online: https://doi.org/10.3389/fpsyg.2016.01251

Fast, B. (2021). “How Our Brains Learn Best: Surprising Practice Tips We Tend to Avoid.” National Conference on Keyboard Pedagogy.

Pan, S. C. (2015). The Interleaving Effect: Mixing It Up Boosts Learning. Scientific American, retrieved online: https://www.scientificamerican.com/article/the-interleaving-effect-mixing-it-up-boosts-learning/