If you’ve ever spent time with a Yamaha Harmony Director Keyboard, you know it’s one of the most valuable tools a music educator can own. It’s one of our favorite recommended resources!

Our new Online Director Keyboard is not meant to replace a Harmony Director Keyboard. Instead, it’s designed as a portable, always-available introduction to drone tuning and the differences between pure (just) temperament and equal temperament.

Think of it as a pocket-sized cousin of the Harmony Director, ideal for clinicians, marching band staff on the football field, or anyone working with students on the go. It’s also a great starting point if you don’t have access to a Harmony Director Keyboard yet, but want to start exploring equal and pure temperament with your students.

About Pure Temperament in This App

Our Pure Temperament mode is based on the widely shared “Chords of Just Intonation” handout that has been used by educators for years (view here or a similar resource). This has become a mainstay in band and orchestra pedagogy circles in particular.

This tuning method works beautifully with those chord qualities and will automatically select the most likely chord from what you play. You can also set the root manually for more control.

While it’s not a complete just intonation system for all possible chords, it’s a highly practical and immediately useful introduction to the concept to ensembles getting used to listening for pure intervals. If you create a chord outside of those chord qualities in our app, your results will vary.

💡 Features

  • Two Temperaments

    Switch between Equal Temperament (what most modern instruments use) and Pure Temperament for hands-on comparison.

  • On-Screen Piano

    Click with your mouse or tap on touch devices to play notes. Works with or without “Hold” mode engaged.

  • MIDI Input

    Plug in a MIDI keyboard for full playability and temperament switching.

  • Drone Mode

    Set a sustained pitch or chord to give your ensemble a solid reference. These can be individually pitch adjusted.

  • Metronome

    Metronome with quarter, eight, triplet, and 16th note sliders.

  • Waveform Selection

    Choose between Sine, Triangle, Square, and Sawtooth waveforms to change timbre

  • Adjustable Volume

    Separate sliders for keyboard and drone volumes.

  • Custom Root Selection

    Manually set the root when using Pure Temperament for specific chord tuning.

  • Portable

    Runs entirely in your browser—no installation needed, works on phones, tablets, and desktops.

How Directors Can Use It

  • Before rehearsal: Set a drone in pure temperament for your warm-up chorales.

  • During sectionals: Demonstrate tuning differences between equal and pure temperament.

  • On the field: Keep a phone or tablet handy for on-the-spot intonation checks.

  • In lessons: Let students hear how a third locks in when tuned purely versus equally.

  • For ear training: Play intervals and chords, asking students to identify when they’re in tune.

Walkthrough Video

🛠 Under the Hood

This application was built using:

  • HTML, CSS, and JavaScript — for the main interface and controls.

  • Web Audio API — to generate the different waveforms and handle pitch adjustments.

  • MIDI API — for live input from connected keyboards.

  • Custom Just Intonation Mapping — derived from the Chords of Just Intonation chart, applying cent offsets for pure tuning.

The entire app is front-end only, meaning it works anywhere without installing software or sending data to a server. I built this with help from Chat GPT 5.

Try It Now

Launch the Drone Tuning & Temperament Trainer

No sign-up, no downloads, just open and play.

This is our beta release, and we’re excited to put it in your hands. We’ve tested it extensively, but real-world use by directors, students, and clinicians will tell us what works best and where we can improve. Try it out in rehearsals, sectionals, or on the field, and let us know your thoughts. Your feedback will help shape future updates and features so this tool can be as useful as possible for music educators everywhere.

P.S. - More about the Harmony Director Keyboard

If our application got you excited and tuning systems and harmony, this is a great recommended video on the added benefits of investing in a Yamaha Director Keyboard for your classroom as well as some of the ways to talk about tuning with your students.