Turn a Single Chord Progression Into a Finished Song With AI

Some songs start with a melody. Others start with words. A surprising number start with a chord progression — three or four chords you found while messing around on a guitar or piano, that loop in a way that feels like it *wants* to be a song.

For most of music history, "chord progression that feels like a song" was the start of weeks of work — finding a melody, writing lyrics, recording, producing. In 2026 the progression itself can be the whole input. Here's how to take a chord loop from "this feels like something" to "this is a finished song."

The chord-progression bottleneck

Songwriters who play instruments tend to discover great progressions accidentally — fingers wandering across the fretboard or keyboard, a sequence emerges that feels right. The bottleneck has always been the next step: figuring out what melody fits, what the song is about, what genre to commit to, who should sing it.

Most interesting chord progressions die in the bottleneck. A folder of voice memos labeled "cool chords" is the universal songwriter's graveyard.

The 4-step chord-to-song flow

1. Record the progression. Play the chords into Larka's recorder. Larka detects the chords, key, scale, and BPM automatically.

2. Pick a feeling. Genre + mood. The chord progression can fit many genres — your choice steers the song's identity.

3. (Optional) Drop in a lyric or theme. A one-line idea is enough. Without one, the AI will write its own.

4. Generate a full song. The AI uses your chord progression as the harmonic spine and builds melody, vocals, instruments, and arrangement around it.

In 90 seconds you have a song that uses *your* progression as its bones. The melody you didn't have to write is fitted to the chords you did write.

Why this works musically

Chord progressions imply melodies. The notes in a key constrain which melodic lines will sound consonant; the chord changes guide where melodic emphasis falls. AI vocal models trained on songwriting data have absorbed these implicit rules — they generate melodies that fit the harmonic context.

The melody won't be the melody you would have written. It might be better; it might be worse; it will definitely be different. What matters is that it *fits* — it sits in the key, lands on the right beats, hits chord tones at chord changes.

If you don't love the melody, regenerate. Each generation produces a different melodic interpretation of your same chord progression.

When to constrain and when to set the AI free

Tight constraint: record the progression, set genre and mood specifically, drop in a detailed lyric idea, generate. The AI fills in the gaps but the song is largely shaped by you.

Loose constraint: record the progression, set just genre, let the AI invent the lyric and melody from scratch. You'll discover what the progression "wants" to be in a way you couldn't have predicted.

Both are valid. The loose-constraint approach is good for learning what your progression is capable of. The tight-constraint approach is good for delivering a specific song.

Using the chord progression you didn't write

Quick aside on legality: your *own* chord progression is yours. But chord progressions themselves are *not* copyrightable in most jurisdictions — only specific melodies and lyrics are. So building a song on top of a famous progression (the I-V-vi-IV "Don't Stop Believin'" pattern, the "canon in D" descent, the iiø-V-i jazz cadence) is legally fine.

What matters legally: don't reproduce the original's melody, don't replicate the original's lyrics, don't use the original recording. The chord changes alone are public domain in practice.

This is what makes the chord-to-song workflow especially interesting for cover-band guitarists and worship musicians whose ears are full of progression patterns from songs they've played thousands of times — those patterns are reusable raw material.

Iterating on the progression itself

If your generated song is close but not quite, you might be tempted to regenerate over and over. Sometimes the better move is to change the *progression*, not the parameters around it.

Try: add a passing chord between two chords that feel too static. Try a borrowed chord from the parallel minor (or major). Try the progression in a different inversion. Re-record. Re-generate.

The Circle of Fifths screen in Larka shows neighboring chords that "fit" your current progression — quick way to discover variations without theory knowledge.

From AI song back to you playing it

Once you have a generated song you like, you may want to play it yourself live. Larka exports the chord chart and timeline as MIDI for use in a DAW, or as a screenshot you can paste into a rehearsal note.

The AI-generated melody is also playable — listen carefully, learn it, sing it yourself. You've essentially commissioned a co-writer to write a melody to your chord progression. The melody is now part of your song. Performing it yourself is the natural next step.

What this changes for guitarists and pianists

If you play an instrument and your songwriting bottleneck has always been "great chords, no melody," that bottleneck is gone. The chord progression you found this weekend can be a finished song before Sunday night.

The slower, harder work of *good* songwriting (lyrics that mean something, structure that builds) is still yours. But the *technical* work of fitting a melody to a progression — the part that used to take years to develop the ear for — can now happen in 90 seconds.

Most players who try this workflow once leave their voice memos folder behind for good. The graveyard finally has fewer occupants.