My music theory is what a kind person would call 'functional' and an honest person would call 'I know a I-IV-V and I once heard the phrase secondary dominant at a party and nodded confidently.' Seven years of guitar, three years of producing, and my actual method for writing a chord progression has always been to noodle around in a key until my hands stumble into something that doesn't make me physically wince. This works. It is also painfully slow, and the deeper problem is that it means I never understand WHY the good ones are good, so I can't ever repeat the trick on purpose. I just have to get lucky again.
The brief I generated on a random Tuesday night
I had a half-written indie-folk thing that I wanted to start sad and end warm — that classic 'crying in the first verse, hugging by the outro' emotional arc that every good folk song seems to nail and I never could. So I ran the Chord Progression Brief with Roman Numerals and Theory Notes prompt on Claude Sonnet 4.6. Genre: indie folk. Mood and energy: melancholic open, resolved and warm by the end. Key preference: minor, Dm or Am. Length: 3.5 minutes. Reference feel: Sufjan Stevens shaking hands with Big Thief in a quiet room.
What came back was not just chords. It was a full brief — Roman numerals AND Nashville numbers for every single section, a structure timeline with rough timestamps to fit my 3.5 minutes, arrangement notes telling me what enters and exits in each part, and then the section I didn't know I was absolutely starving for: Theory Notes, which explained the harmonic decisions in plain, patient English like it was talking to a friend instead of a textbook.
The bVII chord, finally explained like I'm a person
Here is the move that paid for the entire prompt and then some. Sonnet put a bVII chord in the pre-chorus and then, crucially, instead of leaving me to nod and pretend I understood, it explained exactly why. The bVII is borrowed from the parallel major, it sits a whole step below the tonic, and dropping into it creates a lift and a slight unresolved ache that makes the chorus land twice as hard when you finally resolve home. I have played I-IV-V for SEVEN YEARS and never once understood that I was allowed to reach OUTSIDE the key for tension on purpose. That single paragraph genuinely rewired how I write. I have deliberately put a bVII into three songs since, and now I know what it's doing.
- I mapped the entire song structure before I opened the DAW for the first time ever in my whole process — usually I structure by stumbling.
- Learned the bVII borrowed-chord move AND the actual reason it works, so I can deploy it intentionally instead of hoping I trip over it.
- An arrangement note told me to pull the drums entirely out of verse two for contrast — I tried it and it was completely, obviously right.
- Finished the track and posted it. It was the longest finished song I'd made in two full years.
Why I specify the exact key instead of letting it choose
Small input, enormous payoff: I wrote 'minor, Dm preferred' in the key preference field instead of just lazily typing 'minor.' Claude didn't pick a random dark key and shrug. It explained that Dm carries a heavier, more somber gravity than Am for the same melody, suggested I sit in Dm for the verses to establish that weight, then resolve briefly to F major — the relative major — in the bridge to actually deliver the 'warm by the end' arc I'd asked for. That is a real compositional decision with a real, stated reason, not a slot-machine pull dressed up as expertise. I've found the more specific my key preference, the sharper and more useful the reasoning gets.
The honest caveat
It's a theorist, not a pair of hands. A couple of times it suggested a voicing that was technically beautiful and physically awkward to actually play on guitar without growing a sixth finger, and I just swapped in an easier inversion — no harm done. And the timeline timestamps are a sketch, a proportion, not a stopwatch you should obey to the second. Treat them as 'roughly here,' not 'exactly at 1:42.' But as a way to both GET a usable progression AND understand the engine under the hood, nothing else in my process even comes close. I genuinely retained more from a handful of these briefs than from a whole stack of theory videos, for one simple reason: the lesson was attached to a song I actually cared about finishing.
If you noodle until something feels right and can never explain the magic afterward, grab the Chord Progression Brief with Roman Numerals and Theory Notes prompt on Prompt Dock and run it on your next stuck track. Then take the lyric it deserves from my Verse-Chorus Lyric Engine — Theme to Recordable Song with Meter Lock prompt, and you'll have words and harmony both pointed at the exact same feeling instead of fighting each other.