Build Chord A
Select a root and chord quality. The tool calculates its pitch classes from the chord formula.
This common tone chord finder compares two chords and instantly reveals the notes they share. See common tones, notes unique to each harmony and the pitch-class relationship between the chords. Discover more practical music resources in Audio Tools for Musicians, or return to Ronter Sound.
Choose any two supported chords and compare their pitch classes.
Two chords can sound different while still containing some of the same notes. A common tone chord finder makes that relationship visible by expanding both chord symbols into their individual pitch classes and finding the intersection between them.
Select the root and chord type for Chord A, then do the same for Chord B. The tool builds both chords from interval formulas, compares their twelve-note pitch-class sets and highlights every note that belongs to both harmonies.
The comparison does not depend on octave or inversion. C3 and C5 are treated as the pitch class C because the purpose here is to discover which note names the harmonies share, not where those notes sit in a particular voicing.
For a broader collection of interactive listening and music exercises, visit Audio Tools for Recording, Mixing and Ear Training.
Select a root and chord quality. The tool calculates its pitch classes from the chord formula.
Add the second harmony and compare its notes directly with the first.
Shared tones are separated from notes that belong only to one of the two chords.
A common tone does not have to be the root of either chord. Any pitch class appearing in both harmonies belongs to their shared harmonic material.
A common tone is simply a note contained in both chords. For example, C major contains C, E and G, while A minor contains A, C and E. The two harmonies therefore share C and E.
Extended chords can create even larger intersections. Comparing the notes directly is useful because chord symbols alone do not always make every shared pitch immediately obvious, particularly when seventh and ninth chords are involved.
This can be useful while planning instrumental layers before recording instruments. A sustained note does not necessarily need to change simply because the chord symbol changes; if that pitch belongs to the next harmony too, it can potentially continue as a shared tone.
Finding shared notes gives composers and arrangers another way to look at harmonic connection. Instead of treating each new chord as a complete replacement of the previous one, you can see which part of the harmonic material remains available.
That can be useful for sustained keyboard notes, guitar parts, pads, string writing, background vocals and layered arrangements. A shared note can become an anchor while other notes around it change.
When those ideas move from arrangement into performance, the music recording process introduces further choices involving articulation, register and tone.
Inverting a chord changes which chord tone appears in the bass and can change the register of its notes. It does not change the underlying set of pitch classes belonging to that chord.
That distinction matters here. The finder answers “Which notes belong to both chords?” rather than “Which physical voice should move where?” Once you know the shared material, you can decide how those notes should actually be voiced in an arrangement.
For musicians preparing a song before their first session, the First Time Recording Studio Guide covers practical preparation beyond the harmonic planning stage.
The note identities contained in two selected chord formulas.
C in different octaves still represents the same shared pitch class.
See the intersection together with the tones found only in each chord.
A common tone chord tool can be used as a quick harmonic comparison whenever you want to understand what two chords have in common. It is useful for songwriting, arranging, harmony practice and studying how chord changes preserve or replace notes.
These two seventh chords share three pitch classes even though their roots are different. The first harmony contains C while the second contains D, but E, G and B appear in both.
Looking at the intersection can suggest several arrangement choices: one or more shared notes might remain sustained, become part of a repeated figure, or serve as stable tones while another layer defines the changing harmony.
One practical use is comparing possible neighboring chords while writing a progression. Enter the chord you already have, then change Chord B through several possibilities and watch how the intersection changes.
A larger number of shared notes means the two chord formulas overlap more heavily. A smaller intersection means more pitch classes change. That information describes the relationship; it does not tell you that one choice is musically better than another.
Songwriters can use the result while developing harmonic material before moving into song demo production. The musical effect still depends on rhythm, melody, register, voicing, instrumentation and performance.
Start with Cmaj7 as Chord A. Compare it with Am7, Em7, Fmaj7 and G7. Instead of only reading the resulting chord names, watch which notes repeatedly remain in the shared section and which pitches enter or leave the harmony.
Shared notes can be particularly interesting in vocal arrangements. If one harmony voice is already singing a pitch that also belongs to the next chord, that note can sometimes remain available while surrounding parts change.
Whether the singer should actually sustain it is an arrangement decision, but identifying the shared note gives you the option. When the arrangement is ready to record, the page on vocal recording covers the performance and recording side of the process.
For artists who are still developing confidence before recording, Musician Psychology and Recording Confidence explores preparation from a different perspective.
The same principle works when harmony is spread across several instruments. A guitar, keyboard or sustained synth may already contain a note required by the following chord. Another instrument can introduce the tones that actually define the harmonic change.
This is one reason it can be helpful to think about arrangements as interacting parts rather than repeatedly assigning a complete block chord to every instrument.
Different styles distribute harmony differently. The music genre recording overview looks at the wider relationship between style and production, while blues and country recording provides a more focused example of genre-specific instrumentation.
The finder supports common triads as well as several seventh, sixth, suspended and ninth-chord formulas. This makes it possible to compare simple three-note structures with harmonies containing additional chord tones.
For example, adding a seventh can introduce another possible point of intersection with a neighboring harmony. Extensions may increase the amount of shared pitch material even when the two chord roots remain different.
The 12-note map beneath the main result is useful here because it shows the entire chromatic pitch-class space at once. Notes belonging to both chords are highlighted, while the remaining positions stay visually separate.
Two chord pairs can contain the same number of shared notes and still sound very different. Chord function, bass movement, spacing, melody, rhythm and timbre all contribute to the result.
Even the same pair of chords can behave differently when played in another register or distributed among different instruments. This finder deliberately isolates one question—the pitch classes shared by two harmonies—so you can inspect that relationship clearly.
Once an arrangement has been recorded, balance and tone become a separate part of the process. You can experiment with those concepts in the Interactive Online Audio Mixer or explore hands-on console controls with the Mixer Console Simulator.
Finding common notes can help organize harmonic material, but a finished track also depends on performance, recording, editing, balance and production decisions. The useful part of the exercise is knowing exactly what stays harmonically available as one chord changes into another.
After the musical parts are recorded, the focus can shift toward how those layers work together sonically. The overview of mixing and mastering describes that later stage, while audio engineering provides a broader view of technical work around recorded sound.
Continue with practical resources for music preparation, recording, listening and production.
Choose another pair above and compare their shared notes, or continue exploring the full collection of audio tools for musicians.
Go beyond individual audio tools. Arrange multiple tracks, edit clips, build modular effect chains, add modulation, mix through a Master bus, save projects and export the finished mix to WAV.
Explore 168 free browser-based tools for musicians, singers, producers, engineers and creators. Open a category to find your next tool.
I build Ronter Sound Lab and the audio tools on this website as free resources for musicians, producers and creators. If these tools are useful to you and you would like to support the project, any voluntary contribution helps me continue developing the free online DAW, create new tools, improve existing features and keep everything available to everyone.
Every contribution, large or small, is sincerely appreciated. Thank you for supporting independent development.