The short answer
Build the chord from intervals first, write down the notes, then check them against a free reference. Melodician is a free site with a dedicated page for each of 180 piano chords, showing notes, fingering, inversions and audio. On 1 October 2026 we opened its Cmaj7, Am7 and G7 pages and the notes matched what the interval formulas give: C E G B, A C E G and G B D F. We have not tested it ourselves at a keyboard, and we have no relationship with its owners.
In our guide to piano intervals we said that every chord is a stack of intervals. That is a useful idea, but it leaves a practical problem. You work out a chord on paper, and then what? Nobody is standing next to you to say whether Am7 really contains a G. This article gives you a simple build-then-check workflow, using a free chord reference as the second opinion.
Who this is for, and who it is not for
- For you if you have read about intervals and want to turn them into chords you can trust.
- For you if you are an adult beginner who would rather understand why a chord has its notes than memorise 180 shapes.
- Not for you if you want songs, sheet music or lyrics. A reference like this answers “what notes are in this chord?”, not “how do I play this song?”.
- Not for you if you need a teacher to correct your hand position or timing. A web page cannot do that.
The interval formulas you need
Count in semitones, where one semitone is the step from one key to the very next, black keys included. Each seventh chord is three thirds stacked on top of each other, and what changes is whether each third is major (4 semitones) or minor (3 semitones).
| Chord type | Stack from the root | Intervals above the root | Example on C |
|---|---|---|---|
| Major seventh | major 3rd + minor 3rd + major 3rd (4+3+4) | major 3rd, perfect 5th, major 7th | C E G B |
| Minor seventh | minor 3rd + major 3rd + minor 3rd (3+4+3) | minor 3rd, perfect 5th, minor 7th | C E♭ G B♭ |
| Dominant seventh | major 3rd + minor 3rd + minor 3rd (4+3+3) | major 3rd, perfect 5th, minor 7th | C E G B♭ |
If you want a refresher on why a major third sounds bright and a minor third sounds darker, our piece on major versus minor covers it.
Step 1: Build the chord on paper
Do this before you look anything up. The whole point is to test your own working.
Cmaj7 (major seventh)
Start on C. Go up a major third (4 semitones) to reach E. Add a minor third (3 semitones) to reach G. Add another major third (4 semitones) to reach B. Result: C E G B. As a check, C to B should be 11 semitones, a major seventh, and 4+3+4 is indeed 11.
Am7 (minor seventh)
Start on A. Up a minor third (3 semitones) gives C. Up a major third (4) gives E. Up a minor third (3) gives G. Result: A C E G. A to G is 10 semitones, a minor seventh. Notice that Am7 shares three notes (C, E and G) with Cmaj7 and differs by one: A where Cmaj7 has B. That is why the two chords sound related, and why it helps to check each chord on its own rather than assuming.
G7 (dominant seventh)
Start on G. Up a major third (4 semitones) gives B. Up a minor third (3) gives D. Up another minor third (3) gives F. Result: G B D F. G to F is 10 semitones, a minor seventh. The B and the F sit a tritone apart, which is where the characteristic tension of a dominant seventh comes from.
All three of these use only white keys, which is a nice property for a first exercise. If you ever feel lost on black-key names, our page on the black keys helps.
Step 2: Check it against Melodician
Melodician is a free chord reference covering guitar, piano and ukulele. We opened the site on 1 October 2026 and went through its piano section. We read the pages and checked the notes. We did not play the audio or practise the fingerings, so we cannot vouch for how they feel or sound in use.
Chord pages follow the pattern melodician.com/piano/ followed by the chord name, for example /piano/cmaj7. Here is what each of our three pages said.
| Chord | Our build | Notes listed on the page | Formula shown | Match? |
|---|---|---|---|---|
| Cmaj7 | C E G B | C, E, G, B | 1 3 5 7 | Yes |
| Am7 | A C E G | A, C, E, G | 1 ♭3 5 ♭7 | Yes |
| G7 | G B D F | G, B, D, F | 1 3 5 ♭7 | Yes |
That is the “1 3 5 7” shorthand you will see in theory books: the numbers are scale degrees counted from the root, and a flat sign means that note is lowered by a semitone from the major-scale version. It lines up exactly with our interval table above.
What else the chord pages show
- Keyboard diagrams for the root position and each inversion.
- Right-hand fingering (on Cmaj7: thumb on C, index on E, middle on G, little finger on B) and a left-hand version.
- Inversions written out with the notes, for example Cmaj7 first inversion as E G B C, with a short description of how each sounds.
- Audio you can tap, per chord voicing and note by note, according to the site.
- Links to related chords, such as C, Dm7, G7 and C7 from the Cmaj7 page.
What we verified about the site itself
| Claim | What we saw | Source, checked 1 Oct 2026 |
|---|---|---|
| Piano chord pages | 180 distinct piano chord links on the piano hub page | melodician.com/piano |
| Cost | Free; the site says no login, accounts, paywall or ads | melodician.com home page |
| Operator | Emsora, MB, a Lithuanian company founded 6 August 2025, per its About page | melodician.com/about |
| Songs and tabs | Says it does not reproduce tabs or lyrics; only chords | melodician.com/about |
| Print and left-handed views | Stated on the site; we did not try them | melodician.com home page |
Step 3: If it does not match
A mismatch is useful information. The usual culprits, in order of how often they happen:
- You mixed up the third or seventh. Minor third is 3 semitones, major is 4. Recount.
- You wrote the wrong accidental. A minor seventh above G is F natural, not F sharp.
- You built a different chord type. Cmaj7 and C7 look similar in text but differ by one note (B versus B♭).
- The page is showing an inversion. The same notes in a different order are the same chord, so check the root-position diagram first.
Where this reference stops
- Chords only. It does not teach songs, rhythm patterns or voice leading. For turning chords into actual songs, see how to play pop songs on piano.
- No feedback. It shows the answer; it cannot tell whether your hands are doing it correctly. Our note on left versus right hand is a better place to start on that.
- Very new. The operator was founded in August 2025, so we cannot speak to long-term reliability. Cross-check anything surprising against a second source.
- Independent and unreviewed by us at the keyboard. We checked notes against theory; we did not judge the audio quality or fingering comfort.
If you are wondering how much of this theory you actually need, see do you need music theory to play piano. Short version: a little goes a long way, and chords are the best place to spend it.
FAQ
Is Melodician really free?
That is what the site states, and we met no login or paywall on the pages we opened on 1 October 2026. Terms can change, so check the site yourself.
Do you have a relationship with Melodician?
No. We are not paid by Melodician, we have no affiliate link to it, and we have no commercial relationship. This article has no affiliate link to Melodician. The Pianoforall button at the bottom of every page on this site is an affiliate link.
Why do Am7 and Cmaj7 look so similar?
Both use only white keys and share three notes, C, E and G. Cmaj7 adds B on top of that triad; Am7 adds A underneath. Different root and a different extra note make them two separate chords with different roles in a key.
Can I use this for chords beyond sevenths?
The site lists many other chord types for piano, though we only inspected three pages in detail. Use the same method: stack the intervals, write the notes, compare.
Should I memorise the shapes or the formulas?
Formulas scale better. Three formulas cover all twelve roots, whereas shapes multiply. Use the reference to confirm, not to replace understanding.
Transparency note: we are a review site run by a marketer, not a piano teacher. Theory facts come from the Wikipedia seventh chord article and our own interval guide; facts about Melodician come from its public pages as read on 1 October 2026. This article has no affiliate link to Melodician. The Pianoforall button at the bottom of every page on this site is an affiliate link.