The Improviser · Lesson 3 — The Specifics ← Course

The specifics — pin it down.

A brief only steadies the playing if it's specific. Say little, and you get a different solo every take.

Swapping the brief changed how the improviser played. But a brief is only as good as it is clear. Tell the player to "play something nice" and you've said almost nothing — so you get a different, often unusable solo every time.

Being specific is the fix. A sharp brief pins down a handful of things: the role to play, the rules to follow, the shape the answer should take, what to do when unsure, and the tone. Each piece you pin down is one less thing left to chance.

It's the gap between telling a player "do your best" and handing them a full chart — the key, the chords, how to end. With a real model, that chart is the system prompt: the standing instructions it reads before every request. The more precisely the job is defined there, the more consistent every answer becomes.

Start from a vague brief and add one specific piece at a time. Watch — and hear — the solo tighten from a shapeless ramble into a clean, repeatable phrase.

A vague brief — the improviser barely knows what you want. Add a piece.
the brief · system prompt
+ ↓
the tune · unchanged
Two bars over a C-major vamp.
↓
the solo · vague

Five things, pinned down.

A strong brief is just a handful of clear lines — role, rules, format, edge cases, tone — handed to the model as a single system instruction. 

system = """
You are an improviser on a two-bar C-major vamp.   # role
Stay in key; resolve onto a chord tone (C, E, G).  # rules
Reply as up to six note names, then one reason.    # format
If unsure where to land, resolve to the tonic C.   # edge cases
Keep it clean and neutral — no showboating.        # tone
"""

Specific in, consistent out.

A vague brief might land a fine solo once and a poor one the next time. Each specific piece you added — role, rules, format, edge cases, tone — took one more thing off chance, until the same clean phrase came back on command.

Consistency is the real prize. Swapping the brief changes the manner; making it specific is what turns a good answer into a repeatable one.

Quick check · your ear
Why did adding "resolve onto a chord tone" and "reply as six note names" steady the solo?
On to Lesson 4 →
▸ Go deeper — writing briefs that hold optional

Specific beats long

A good brief isn't the longest one — it's the one that leaves the least to chance. Five sharp lines usually beat five paragraphs of throat-clearing. Padding costs tokens (the window's rent from Lesson 2) and buries the instructions that actually matter.

Name the edge cases on purpose

The line that earns its keep most often is the "when unsure, do X" one — here, resolve to the tonic. Models are least predictable exactly when the input is ambiguous, so telling them where to land in a close call is what turns a sometimes-good answer into a reliable one.

Format is a lever, not decoration

Pinning the shape of the reply — "six note names, then one reason" — does double duty: it makes the answer easy to use downstream, and it quietly constrains the model into the behaviour you want. Much of prompt-writing is just choosing the output shape and the fallback, then getting out of the way.