When you need to find the key of a song in a pinch, these top 5 key detection plugins of 2022 are often faster and more effortless than manual attempts.
Whether you’re making a mixtape or trying to incorporate an awesome acapella in your instrumental, finding the chords of the two musical audio clips is the first step to ensuring they fit together. For example, once you know the tonic and the chord progression of a vocal recording, you can modify it to match the melody with your music. Similarly, knowing the key of your samples and loops helps you create a coherent piece of music.
However, unless you have undergone ear training for several years, you will have difficulty finding the chords of a song or sample quickly, even if you play the piano or guitar. Hence, we have plenty of tools that detect the scale of your audio, which in turn helps you find the correct chords. Some of them are websites that analyze audio to produce a chord chart. Similarly, others are phone apps that work remarkably well.
In a nutshell, here are the best key detection plugins & software in 2022:
- 1. Zplane Tonic
- 2. Mixed In Key Studio Edition
- 3. Antares AUTO-KEY
- 4. PluginBoutique Scaler 2
- 5. HoRNet SongKey MK4
In this article, I will enlist and review six of the best key detection plugins available on the market. You can use these in your DAW to analyze any audio on the track. Furthermore, most of these work in real-time. So, a cool trick I like is using the plugins with a chord detector as chord visualizers when recording or improvising an instrument solo.
Top 5 Key Detection Plugins 2022
1. Zplane Tonic
Tonic is a straightforward “music theory” tool that supports key detection with multiple scales.
Sometimes, a song can have more than one scale. Therefore, Tonic provides you with all the possible keys of the music so that you can decide which one fits best. And you can test out the scale inside the plugin. It has a very user-friendly interface, real-time functions, and other features that help music production.
Using the plugin is as easy as placing it on a track with the song and hitting play. Furthermore, since some music is made in offset tuning where A≠440 Hz, Tonic’s reference tuning engine automatically identifies such tuning. You can use the plugin on full songs or acapella and solo instruments.
- Dual Modes
When you load Tonic, it opens the plugin in the “real-time” mode by default. You can play any audio like a vocal recording or a full-on instrumental track in this mode, and Tonic will detect its key or scale in real-time. This mode is great when you need to analyze a specific part of a track for using it in, say, a mixtape.
Similarly, Tonic features an “offline” mode that lets you load audio files and analyze the entire clip quickly. This method works faster as you don’t have to wait for the track to play in real-time. Click on the File tab at the top of the plugin’s interface to find the offline mode.
- Triple Scales
Some musical pieces use multiple scales, whereas some genres like blues or jazz use a lot of accidental notes. These can create false readings. Hence, Tonic displays three possible scales listed by their probabilities. In the screenshot above, you can see Fmaj, A#maj, and Dmin. The order of the scales and the colors in the ring around the list represent the possibilities of each scale.
- Keys & Chords
The virtual keyboard allows you to play the detected scale in the plugin. Furthermore, you can activate the “Fold Keys” mode to make it display only the notes in the scale. Similarly, switch to Chords mode to play the compatible chords in the scale. It makes finding the chords of a song a piece of cake.
- Sharps or Flats
While a scale technically has both sharps and flats depending on the relation of the note to the adjacent scale degrees or notes, many people nowadays tend to prefer one or the other. Hence, Tonic allows you to set the plugin to either use the sharps or flats. It’s a fairly minor feature, but it can add a lot of convenience for people who haven’t studied music theory in depth.
This plugin is available for Windows 10 or higher and macOS 10.15 or higher, both 64-bit only. It comes in VST 3, AU, and AAX formats.
If you are after a simple key detection tool that doesn’t display an overwhelming amount of information, Tonic is an ideal choice. Its key detection engine is very accurate, and it supports both real-time and offline modes. Furthermore, the plugin’s built-in keyboard is an excellent feature to try out the detected key and discover the chords in the scale. I’d have loved to use the Chords mode without using the key detection feature, though, which felt like a missed opportunity to me. Still, it’s nifty for what it promises to do.
2. Mixed In Key Studio Edition
Mixed In Key Studio Edition is one of the easiest key detection plugins with detailed note information.
Mixed In Key SE is dedicated to producers who use a lot of samples in their music production. It helps you find the key of melodic samples and the tuning of your percussions and drums. So, if you produce hip-hop, trap, EDM, etc., Mixed In Key SE can save you a lot of time and effort.
- Notes Mode
The Notes Mode is the default mode of this plugin. It shows a row of all twelve chromatic notes, and vertical meters show which notes are playing at the moment in real-time. Furthermore, you’ll find the detected key at the top of the interface.
This mode is also useful for detecting the tuning of a sample, whether it’s harmonic or percussive. Similarly, I also found it handy to analyze advanced chords like an add9 or a sus4, which would most likely throw off other detection software. While Mixed In Key SE doesn’t detect advanced chords itself, it allows you to manually identify and verify the chord by providing all the played notes.
- Keys Mode
In Keys Mode, you’ll find a similar interface as the Notes Mode. However, instead of one row of chromatic notes, you’ll find two. The row on the left represents the minor keys, whereas the row on the right represents the major keys. If Mixed In Key SE detects more than one key, it will use a vertical meter in each key it detects to show you the possibility percentage.
Furthermore, this mode also helps you identify key or chord changes in real-time. For example, if a piece of music goes from D minor to F major, you’ll get a real-time visual back as the chord changes occur.
- Key Notations
The Key Notation switches let you change the nomenclature of the black keys on a piano. Set it to sharp or flat according to your preference to speed up your workflow. However, it also features a “Camelot” mode, which uses a simplified circle of fifth to help you find harmonically pleasing chords faster.
Mixed In Key SE is available for Windows 7 or higher and macOS 10.10.5 or higher, both 64-bit only. It comes in VST 2, AU, and AAX formats.
Mixed In Key SE is a straightforward key detection software, ideal for contemporary producers who use a lot of samples and loops. It displays all the played notes in the audio as well as multiple keys or chord changes. The plugin is also quite accurate, regardless of whether you’re analyzing a single note or a full mix. Also, if you like how this plugin works, make sure you check out my list of the best chord generators, which features one by Mixed In Key too.
3. Antares AUTO-KEY
The philosophy of Auto-Key is simplicity with its minimalistic approach to key detection.
Antares is the developer of the renowned real-time pitch correction software Auto-Tune. Producers have used it to improve their vocals subtly or create robotic effects. And the next step to assisting you in getting faster results is Auto-Key, which is a real-time scale or key detector.
- Straightforward UI
Auto-Key’s user interface must be one of the simplest interfaces I’ve ever seen. Once you load the plugin on the track with your audio file, it will start detection as soon as you hit play. It takes a few bars of playing for it to analyze the audio accurately.
You’ll find the detected key in the middle of the interface, whereas the top right corner shows the tuning reference, meaning it supports non-standard tuning like A=438 Hz. Furthermore, the virtual keyboard displays the notes in the scale it has detected.
The most significant feature of this otherwise minimal plugin is its integration with Auto-Tune. Once Auto-Key has finished detecting the key, click on Send To Auto-Tune and assign the key to each instance of Auto-Tune in your project simultaneously. It eases and speeds up your workflow by automatically detecting and assigning the key.
- Offline Mode
The File option on the left of the interface allows you to open an audio file into Auto-Key. It analyzes the audio offline and faster than real-time analysis. So, it’s ideal for analyzing samples before you load them into your project.
The plugin is available for Windows 8.1 or higher and macOS 10.13 or higher, both 64-bit only. It comes in VST 2/3, AU, and AAX formats.
Auto-Key is a straightforward key detection plugin developed by a reputable brand. It’s very accurate and comes with a minimalistic user interface. Hence, it is an excellent choice for people who prefer simplicity. However, I find the plugin quite expensive, even after considering the integration with Auto-Tune. Still, if you use Auto-Tune often, this nifty plugin can help speed up your workflow.
4. PluginBoutique Scaler 2
Scaler 2 is a complete suite of music theory tools with a built-in sound library, making it far more than a mere key detector.
Scaler 2 is primarily a chord generation plugin that helps you create chord progressions from scratch using a vast library of built-in scales and genres. Among the many features of this plugin, chord and key detection are handy. Furthermore, in addition to detecting chords from audio, it can also do the same with MIDI clips.
The latter comes in handy when trying to use a complex MIDI loop. For example, many hip-hop producers use MIDI loops of live piano and keyboard. However, finding the chords from the plethora of notes such loops often have can be quite vexing. Hence, Scaler 2 can find the chords for you automatically so that you can spend time building the song rather than puzzling out the loop.
Moreover, the plugin comes in two variations: an instrument plugin and a MIDI effect. The prior features factory sounds, whereas the latter is excellent for generating chords and playing another instrument. And you’ll need to use the instrument plugin for detecting chords and keys.
- Audio Detection
Scaler 2’s chord detection feature goes far beyond the plugins I’ve covered so far. It allows you to extract chords from an audio clip and use them to perform MIDI instruments or write chord clips straight into your DAW. Further, it lets you identify the scale of your audio clip, regardless of whether it’s a monophonic recording or polyphonic.
The plugin comes jampacked with over two thousand scales and modes. Furthermore, you can modify these scales further with various presets and parameters. Similarly, Scaler 2 also features a sound engine with synth leads, pads, piano, and other acoustic instruments. So, it lets you get as creative as you want with exciting scales and chord combinations without ever leaving the plugin.
Scaler 2 comes with a collection of live phrases and patterns that help you write piano and keyboard parts with ease. The phrases update according to your chord progression, whether selected from its library or detected from a song. Furthermore, you can use Key Locking to write melodies by locking your MIDI input to the selected scale or chords.
Scaler 2 is available for Windows 7 or higher and macOS 10.8 or higher, both 64-bit only. It comes in VST 2/3, AU, and AAX formats.
Scaler 2 is an outstanding music theory plugin. It features an accurate engine to detect keys and scales from both audio and MIDI clips. And it also lets you explore new sonic ideas by providing an intuitive way to work with scales. It’s an ideal plugin for music producers who aren’t yet confident in their theory knowledge. However, it may be overkill for someone who just wants a simple key detection plugin.
5. HoRNet SongKey MK4
HoRNet Songkey MK4 is a multi-functional basic music theory tool that makes remixing and loop production effortless.
SongKey originally started as a simple key detection plugin. However, the fourth iteration of the plugin brings in several other features, including chord and tempo detection, better detection algorithm, etc. Furthermore, all of these features come at an incredibly low price, which makes this plugin excellent for any music producer. Let’s have a better look at its features.
The plugin’s interface features two “chromagrams,” the bar graphs with the chromatic notes of an octave. The left one displays the chord that is currently playing, whereas the right one shows the key. The advantage of this setup is that it can detect advanced chords like Suspended or Maj7, unlike most key detection software with support for only major/minor triad. Furthermore, the graph also shows which notes are playing to form the chord and the notes in the detected scale.
- MIDI Out
The MIDI Out feature lets you send the detected chords into a MIDI track to perform or record. I’m a huge fan of this feature because it’s so much easier than writing/performing chords yourself. And if you don’t need the function, you can disable it with a click of a button.
SongKey MK4 comes with a standalone app that lets you analyze the sound from any software on your computer, like a browser, to get real-time analysis. Furthermore, you can use it to analyze a live performance and generate a MIDI clock that keeps a sequencer/DAW in time with the live playing.
The Notation lets you set the terminology for the sharp/flat notes to either sharp or flat. It’s useful when you aren’t used to reading both.
The plugin is available for Windows 7 or higher and macOS 10.11 or higher, both 64-bit only. It comes in VST 2/3, AU, and AAX formats.
SongKey MK4 is an excellent tool that is also affordable. While the past versions may not have been as accurate or fast as competing products on the market, the fourth version makes it on par or better. Furthermore, the chords MIDI out and live tempo detection features make it stand out among other similar plugins.
Best Free Key Detection Software 2022
Antares Auto-Key Mobile
Antares Auto-Key Mobile is the version of the Auto-Key key detection plugin for smartphones.
Auto-Key Mobile provides you a way to use your phone’s microphone to analyze any audio source and find its key. It’s handy to find out the key of a song playing somewhere without bothering to look it up online. Moreover, it has a very minimalistic interface.
The user interface has a single button that you click to start the audio analysis. All you need to do is provide permission for the app to record audio using your phone’s microphone. Then, it detects the key accurately within seconds each time.
Auto-Key Mobile syncs with any computer version of Antares Auto-Tune automatically via a network connection. It sends the key/scale information to your computer in real-time, excellent for live performances.
The app is available for Android 4.1 or higher and iOS 10.0 or higher.
If you often find yourself wondering about the key of a song, having an accurate key detector in your pocket is probably one of the best ideas. Auto-Key Mobile is precise, fast, and available for free. It’s also a great tool to use with Auto-Tune if you are a user.
Zplane’s deCoda is an excellent music transcription tool suitable for music producers and instrument players.
When learning to play or sing a song, it’s crucial to have various information about the piece. Hence, Zplane created deCoda, a standalone program that analyzes any audio file and provides its key, tempo, chords, arrangement, etc. It lets you effortlessly navigate through a musical piece and go over specific parts as many times as you need with comprehensive information.
- AI Functions
deCoda features an intelligent engine that detects a song’s tempo, beat, key, chords, and song structure. It separates an audio clip into various parts like intro, verse, chorus, etc., and displays the detected chords. The next step is to make sure the structure is accurate by making any edits necessary.
The program is well-designed for people who wish to learn a song properly. It allows you to transpose the entire song or parts of the piece to a key that suits you better. Similarly, you can change the tempo without changing the pitch to make learning the song even easier. Then, you can gradually shift the transposition and tempo to the song’s original values as you get better with practice.
- Focus EQ
Focus EQ allows you to isolate a specific instrument in a song. It uses FFT filtering to isolate an instrument or voice so that you can listen to it alone. Similarly, once you’re done figuring out the part, you can switch to Inverted Focus mode to remove the instrument or voice and practice alone. This feature alone makes deCoda an essential tool for every performing artist or instrumentalist.
- Melody MIDI
The software features a built-in piano roll that shows the notes of the song’s melody. Furthermore, it also displays the spectral content of the tune. You can edit the detected melody by selecting the correct notes. Then, you can either play the melody back inside the plugin or export the MIDI clip into your DAW. The next step could be using a program to create staff notations or guitar tabs.
- More Features
deCoda has several other features that help you learn a song. A handy feature is a metronome with the quarter, eighth, and sixteenth beats, one or two bar count-ins, and an automatic upbeat (navigating past the first note by accident) identification. Similarly, you can save your song projects in an internal library and share the projects with others using a single file.
Zplane deCoda is available for Windows 7 or higher and macOS 10.7 or higher, both 64-bit only.
As you can see, deCoda is so much more than a key detection software. From finding a song’s key, tempo, structure, etc., to transposing, changing the tempo, isolating an instrument, and exporting the MIDI of a melody from the song, deCoda provides a comprehensive toolkit for every musician. The key detection feature is probably the least significant in this program! However, if you are an instrument player or singer and often practice singing or playing your favorite songs, you should give this program a try. It lets you stay in control of your practice sessions and get results faster.
How Does Auto-Tune Detect A Key?
Autotune detects a key by analyzing audio, identifying prominent frequencies, and associating these frequencies to musical notes. It finds which notes are most frequent and establish a key. For example, a C4 note is 261.63 Hz, E4 is 329.63 Hz, and A4 is 440 Hz. Autotune identifies them as an A minor chord.
Occasionally, software tools can give wrong results, too, especially with a synth pad or keys sample. For example, if the software is limited to detecting triad chords only, it could see an F Maj7 (F-A-C-E) as either an F Maj (F-A-C) or an Am (A-C-E) chord. Fortunately, many tools nowadays are capable of detecting advanced chords without fail. Still, here are a couple of tricks that have come in handy for me more times than I could count:
When you play the bass guitar, you’ll realize that root notes (the first note of a chord without inversions) sound the most appropriate with any chord. So, if you have an E minor chord, playing the E note on a bass guitar will sound glued to the chord. Conversely, playing other notes of the chord –G and B in our case— will sound comparatively disjointed.
Therefore, try playing the chord’s root note at a lower octave. The second octave on a piano or keyboard and the first (thickest) or the second string on a guitar work best. If the note sounds strange or dissonant to your ears, chances are you have the wrong chord.
Tuners are plugins that you use to tune an instrument like an electric guitar. It detects the note of your audio in real-time. So, if you aren’t practiced with matching chords by ear, you can try adding a tuner to a music clip. It’s not always accurate, but it’ll often detect the root note as it’s usually the dominant note. Next, compare the result with the key detection plugin to verify the chord.
Remixing, creating mashups and mixtapes, DJing, etc., have made knowing the key of a song more important than ever. Fortunately, we live in a time when technology has nothing but more to give. From detailed information about a song straight from a laptop to detecting the key on a smartphone, you have pretty much everything on the market.
If you are looking for a cheap solution to find the tempo, chords, and key of an audio clip, I highly recommend HoRNet SongKey MK4. It even provides a 15-days money-back guarantee if you aren’t satisfied. Similarly, Mixed In Key Studio Edition is an excellent choice that provides equally detailed information about the key, albeit not the chords or tempo. However, it has a reputation for being one of the most accurate key detection plugins on the market.
On the other hand, if you want something much more capable that can help you produce music, I suggest PluginBoutique’s Scaler 2. It tops my list of the best chord generation plugins for a reason. It lets you analyze audio and MIDI clips to detect their keys in real-time, and you can use the detected chords to build phrases and patterns inside the plugin. Furthermore, its vast scale and sound libraries allow you to explore sonic grounds you’ve never ventured before.
Finally, if you are an instrument player like myself, I recommend trying out Zplane deCoda. It is surprisingly affordable and provides more information from a song than any other plugin on this list. However, note that it’s a standalone software program. So, you cannot use it inside a DAW, which is a bit of a bummer for the music producers looking to analyze samples and loops in their production session.
And on that note, we have reached the end of this article. I hope I could share an interesting plugin with you and make your music production a little easier. Until the next time, happy music-making!
Other Plugin Roundups:
Reverb & Delay Plugins:
Amps & Preamps:
Audio Restoration, Calibration & Utility:
Processing & Sound Design:
K. M. Joshi is a multi-award-winning composer and sound designer, specializing in film, game, and TV audio. He enjoys making cinematic music, rock, blues, and electronica.