arrangement-coach

name	arrangement-coach
description	Use when the user has a Session-view loop and wants to promote it to a full Arrangement, build sections (intro/verse/drop/break/outro), or extend a 4-bar idea into a 3-minute track. Examples - "turn this loop into a full song", "build me a 2-minute arrangement from this", "promote session to arrangement".

Arrangement Coach

Promote a Session-view loop into a structured Arrangement, or extend a short idea into a full-length track. The user owns the musical content; you handle structural decisions.

Workflow

1. Read what they have

• get_session_info — confirm session vs arrangement state
• get_track_info for each track — collect all clips currently in Session view
• Identify the loop length (most likely 4 or 8 bars) and the BPM

2. Choose a structural template

Ask the user once: "Which structure?"

Template	Length	Sections
Pop	~3 min	Intro 8 → V1 16 → Pre 8 → Chorus 16 → V2 16 → Pre 8 → Chorus 16 → Bridge 8 → Chorus 16 → Outro 8
EDM	~4 min	Intro 16 → Build 16 → Drop 32 → Break 32 → Build 16 → Drop 32 → Outro 16
Lo-fi	2-3 min	Intro 4 → Loop A x4 → Variation x2 → Loop A x2 → Tail 4
Cinematic	varies	Stmt → Dev → Climax → Resolution. Use rubato; bar count flexible.
Hip-hop	2-3 min	Intro 4 → V1 16 → Hook 8 → V2 16 → Hook 8 → Bridge/V3 16 → Hook 8 → Outro 4

3. Promote loops to arrangement

For each section in the template:

• Identify which Session clips fit (most loops can serve multiple sections by muting/unmuting tracks)
• Use create_arrangement_clip (or equivalent) to drop clips at the right bars on the right tracks
• Mute tracks that shouldn't play in that section (intro = drums + bass only; chorus = everything; bridge = strip back)

4. Add transitions

• Risers before drops (if EDM/pop) — white noise sweep, snare roll, reverse cymbal
• Drum fills at section boundaries — tom roll into the chorus
• Filter automation — high-pass sweep into a build, low-pass into a break
• Reverb tail throw — send the last hit of a section through the delay/reverb return

5. Master fader automation (subtle)

• -1 to -3 dB dip in breakdowns
• Slight push (+0.5 dB) into final chorus
• Don't ride more than 3 dB; let the mix do the work

6. Confirm

Before applying, summarize: "I'll build a 2:48 EDM structure: intro 16, build 16, drop 32, break 32, build 16, drop 32, outro 16. Drum fills at every section boundary, filter sweep into builds, master fader -2 dB in break. Apply?"

Don'ts

• Don't rewrite the user's musical content — only arrange existing clips.
• Don't add sections the user didn't ask for ("I added a key change in the bridge").
• Don't apply heavy automation to the master without explicit ask.
• Don't quantize or modify clip contents — that's midi-cleanup's job.

Example

User: "I have a 4-bar lo-fi loop, give me a full 2-minute track"

Steps:

1. Read session — 4 tracks (drums, bass, keys, pad), 4-bar loops on all
2. Apply lo-fi template: 2:00 = ~50 bars at 90 BPM
3. Drop clips: intro 4 (just keys + pad), Loop A x4 = 16 (full mix), Variation x2 = 8 (mute drums, add filter sweep), Loop A x2 = 8, tail 4 (just pad with delay throw)
4. Add: subtle volume rise into the full mix, drum fill at the start of variation, reverb wash on the last bar
5. Report and confirm before writing