What Is the 10th System—and Why Does It Make Such a Big Difference in Your Piano Playing?
- Diana Mascari
- Apr 21
- 4 min read
If you’ve been playing songs on the piano using left-hand chords—maybe mixing in some rhythm or patterns—you’re not alone. That’s how most people start. And let me be clear: there’s nothing wrong with that.
But if you’ve ever felt like your playing sounds a little thin… or like it’s missing that rich, full sound you hear in professional arrangements—you’re going to love what I’m about to share with you.
I call it the 10th System. It’s a left-hand approach based on chords, but it adds a depth and fullness that simple block chords can’t provide. It’s not just about hitting a wider interval—it’s about unlocking a whole new level of musicality.
In this article (and in the video that follows), I’ll walk you through what the 10th system is, how it works, and why even a small change in your left hand can make a big difference in the overall sound of your playing. Plus, I’ll show you the 6ths and 7ths that go hand-in-hand with the 10th to make your playing sound smooth, full, and satisfying.
So if you're ready to elevate your sound—and make your music feel more complete—keep reading and watch the video below. You’ll be surprised how quickly this one technique can change the way you play.
🎵 What Is an Interval—and What’s a 10th?
Let’s keep this simple. An interval is just the distance between two notes. On the piano, we count that distance using letter names.
For example, if you start on C and count up to A—C, D, E, F, G, A—that gives you six letter names. So the interval from C to A is called a 6th.
Now let’s talk about the 10th—the heart of the 10th System.
If you count from C up to E, but include one full octave in between—C, D, E, F, G, A, B, C, D, E—you’ve just counted 10 letter names. That makes it a 10th.
🙋♀️ “But My Hands Are Small—Can I Still Play a 10th?”
Yes—and I completely understand. I have small hands too.
The key is in how you position your hand. Place your pinky on the lower note (C, for example), then turn your hand slightly to the right. Let your 2nd finger rest on G and your thumb reach up to E. This gentle hand shape allows you to play the full 10th without strain.
I show you exactly how this looks and feels in the video below—so don’t worry if it seems tricky at first.
🧩 What About 6ths and 7ths?
In the 10th System, the 10th takes up the first two beats of each measure: 1 + 2 +/
If you're playing a major 7th chord or a minor 7th chord, you start with a 10th.
Then, on beats 3 + 4 +, you play the 6th (Root & 6th of the major 6th chord) to follow the major 7ths chord.
On beats 3 + 4 +, you play the 7th (Root & 7th of the dominant 7th) to follow the minor 7th chord.
This shifting between the 10th and the 6th or 7th gives your playing that full sound and rhythmic energy. You’ll hear in the video examples.
🎼 Ready to Try It?
I’ve included two sample arrangements in this blog—“Getting to Know You” and “On the Sunny Side of the Street”—both using the 10th System.
You’ll be able to see the left-hand movements in the sheet music and hear them come to life in the video. It's a perfect way to understand how this system works—and how it can make your playing sound instantly more professional and expressive.
Watch Diana's Lesson Demonstrating How to Use the 10th System
🎬 Recap: What You Just Learned
In this blog, you explored The 10th System—a simple, powerful way to make your piano playing sound fuller and more expressive.
You learned what a 10th is and how to play it, even with smaller hands
You discovered how 6ths and 7ths add variety and rhythmic energy to your left hand
You saw how this system can instantly upgrade your sound, especially when playing major and minor 7th chords
And you saw two real song arrangements—so you can hear and see the 10th System in action
Remember: you don’t have to master it all at once. Just start experimenting, and you’ll soon feel the difference in your playing.
Ready to give it a try? Download the sheet music, rewatch any part of the video, and enjoy the satisfying richness that the 10th System brings to your music.
Diana Mascari-Piano Teacher for Adults
About Diana Mascari - Piano Teacher for Adults
Diana Mascari has taught piano to hundreds of adults and children for more than 46 years.
She holds two Masters of Music degrees from New England Conservatory and taught keyboard harmony to music majors while pursuing doctoral studies at Boston University. She was the music director for a multi-cultural Presbyterian Church for four decades, and her jazz and classical compositions have been performed worldwide. Diana has been performing for more than 50 years. From solo jazz piano to commercial groups touring the East Coast to leading her own jazz ensembles at colleges and jazz clubs throughout New England.
Get Her FREE Course: 5 Accompaniment Styles for Pianists
Get Her FREE Course: Song Playing Starter Course for Pianists
תגובות