ChordSonic Charts: September 2026 — the month's top chord loop, key and tempo

Welcome to the first edition of ChordSonic Charts — a monthly look at what the songs people analyse on ChordSonic have in common. Not which songs were uploaded (we never name those), but which chord loop, key, tempo and chord came out on top.

This edition covers everything analysed between 1 and 30 September 2026. The long-run picture, re-counted every month, lives in our main study: what is the most common chord progression?

Two things to keep in mind. The sample is what our users choose to upload — songs they want to learn, cover or practise over — not the radio charts. And every chord, key and tempo here was detected automatically, so read the shares as a good estimate, not a hand-checked transcription. All shares are rounded to whole percentages.

September's champions

Four-chord loop: I–V–vi–IV, comfortably

No surprises at the top. I–V–vi–IV — the "four chords of pop", counted together with its rotations like vi–IV–I–V — was the loop in about one in five of the songs that repeat a clean four-chord cycle. That is more than twice the runner-up, the doo-wop loop I–vi–IV–V, and it held first place in every resample of the month we tried: this lead is not luck.

If you want to know why this loop works so well, the four chords of pop explains it, and the chord player lets you hear it in any key.

Three-chord loop: I–IV–V

Among songs built on a repeating three-chord loop, the winner was the oldest one in the book: I, IV and V — C, F and G in the key of C — whether played upwards (C–F–G) or falling back from V to IV (C–G–F). The two directions are close to a tie on their own, so we count them as one family, and as a family they win clearly.

Second was the IV–V–vi family — F–G–Am in C, or, read from the minor key, the rising ♭VI–♭VII–i that turns up in so many big, cinematic choruses.

Key: a tie between G major and C major

G major and C major share the title: both round to about 8% of songs, and when we resampled the month the two swapped places too often to name a winner. D major was next. The usual guitar-friendly keys — G, C, D, E and A — again filled most of the top of the table.

Detecting a key automatically is harder than detecting chords, especially telling a major key from its relative minor. If you need the key of one specific song, the key finder is the place to start.

Tempo: 120–130 BPM

The busiest ten-BPM band was 120–130 BPM, holding about 18% of songs, narrowly ahead of 110–120 BPM. The median tempo of the month sat at about 124 BPM. To check the tempo of a song yourself, try the BPM finder or tap tempo.

Chord: G

Counting the time every chord is actually sounding, regardless of key, G major filled the most of it — about 9% of all chord time in September — ahead of D major and C major. It is no coincidence that G major is also one of the two top keys: a song's home chord is usually its busiest one.

Two small things we noticed

• 130 BPM was the single most common tempo reading, clearly ahead of 120 and 118. Producers like round tempos, and a song recorded to a click set at 130 stays at 130.
• Loops are common, but not universal. About a third of September's songs repeated a clean four-chord loop and about half a three-chord loop. The rest move through their harmony without settling into one fixed cycle — or our detector's occasional slips break the exact repetition.

What's next

This is the first edition, so there is nothing to compare it with yet. From next month, each edition will say what changed — and only call a change a change when it is bigger than the ordinary month-to-month noise. Small wobbles in a share are expected and we won't dress them up as trends.

Curious where your own song fits? Upload it and you'll get its chords, key and tempo in one go — or look up a single chord in the guitar chord finder, and build new loops in the chord progression generator.