Working Set Envelope

A Working Set Envelope wraps a bounded MRS-S fragment with task-adaptive context for focused agent operations. See: /MRS-Specification-RFC#7-working-set-envelope

Design Principles

Agents read MRS-S — complete, human-auditable score fragments
Scopes use UUIDs — not measure numbers — for structural stability
Task-adaptive context — views tailored to the specific task, not fixed rings
Permissions via bundles — lane bundles grant appropriate modification rights

Envelope Structure

(working-set
  :version 1.0
  :source-hash "sha256:a3f2c1b9e4d7..."
  
  :scope
    (:measures #uuid "018c3f40-002d-..." #uuid "018c3f40-0034-...")
    (:instruments [clarinet-bb])
    (:voices [v1])
  :display-hint (:measures 45 52)
  
  :bundle orchestrate
  :allowed-ops [create-event update-event delete-event create-span delete-span]
  
  :task "Add clarinet countermelody responding to violin theme"
  
  :constraints
    ((range clarinet-bb E3 C7)
     (avoid parallel-fifths violin-1))
  
  :content
    (meta
      :time 4/4
      :key C :mode minor
      :tempo 132)
    
    (instruments
      (instrument clarinet-bb :name "Clarinet in Bb" :abbr "Cl." 
                  :staves [treble] :transposition (down M2)))
    
    (measures
      (measure 
        :id #uuid "018c3f40-002d-..."
        :number 45
        :beat-start 487
        (clarinet-bb
          (v1))))  ; Empty — target for agent
    
    (spans)
  
  :context-views
    (context-view melodic-reference
      :instruments [violin-1]
      :measures #uuid "018c3f40-002d-..." #uuid "018c3f40-0034-..."
      :content
        (measures
          (measure :id #uuid "..." :number 45
            (violin-1
              (v1
                (: 0 G5.q :id #uuid "...")
                (: 1 A5.e :id #uuid "...")
                ...)))))
    
    (context-view harmonic-context
      :content
        (harmony-events
          (chord :measure #uuid "..." :beat 0 :symbol Cm :function i)
          (chord :measure #uuid "..." :beat 2 :symbol Fm :function iv)))
  
  :structural-index-ref "sha256:abc123..."
  
  :available-queries
    [:melodic-content :harmonic-analysis :orchestration-density])

Envelope Fields

Required Fields

Field	Type	Description
`:version`	decimal	Envelope version (1.0)
`:source-hash`	string	SHA-256 hash of source state (conflict detection)
`:scope`	scope-spec	What the agent may modify
`:content`	MRS-S	The score fragment (readable, target of ops)

Scope Specification

:scope
  (:measures #uuid "..." #uuid "...")   ; UUID range (inclusive)
  (:instruments [clarinet-bb flute-1])  ; Instruments included
  (:voices [v1 v2])                     ; Optional: specific voices
:display-hint (:measures 45 52)         ; Human-readable, informational

Important: Scope uses UUIDs for structural stability. Display hints are for human orientation only — never used for structural reference.

Permission Fields

Field	Type	Description
`:bundle`	keyword	Lane bundle granting permissions
`:allowed-ops`	list	Explicit list of permitted operation types

Optional Fields

Field	Type	Description
`:task`	string	Natural language task description
`:constraints`	list	Validation rules agent must satisfy
`:context-views`	list	Task-adaptive context views
`:structural-index-ref`	string	Hash reference to structural index
`:available-queries`	list	Queries agent may request

Content Self-Containment

The :content of a Working Set Envelope MUST be parseable as standalone MRS-S:

Instrument definitions MUST be included
Time/key/tempo state at extraction start MUST be declared
Spans MUST have both endpoints within scope OR be marked with boundary markers

This enables validation of the content independent of the full score.

Task-Adaptive Context Views

Context views provide task-relevant information beyond the edit scope. Unlike fixed “near/far” rings, views are selected and shaped for the specific task. See: Task-Adaptive Context Views

View Types

View Type	Purpose
`melodic-reference`	Melody the agent should respond to
`harmonic-context`	Chord progression and key areas
`orchestration-map`	Active instruments and texture
`phrase-structure`	Phrase boundaries and form
`dynamics-profile`	Dynamics trajectory
`thematic-references`	Themes and motifs

View Selection by Task

Task Type	Typical Views
Countermelody	melodic-reference, harmonic-context
Orchestration	orchestration-map, dynamics-profile
Dynamics pass	phrase-structure, dynamics-profile
Harmonization	melodic-reference, phrase-structure

Boundary-Crossing Spans

When a span crosses the envelope boundary:

(slur
  :id #uuid "018c3f2c-..."
  :from #uuid "018c3f2a-..."    ; Inside scope
  :to #uuid "018c3f2b-..."      ; Outside scope
  :boundary-exit true)          ; Marks endpoint outside

Boundary Rules

:boundary-entry true — span starts outside scope, ends inside
:boundary-exit true — span starts inside scope, ends outside
Both markers — span crosses through scope

Boundary-marked spans are read-only at their boundary endpoints. Agents MAY NOT modify :from, :to, or :events of boundary-marked spans.

Available Queries

Agents may request additional context:

:available-queries
  [:melodic-content    ; Request melody from specific instruments
   :harmonic-analysis  ; Request harmony analysis
   :orchestration-density ; Request texture information
   :phrase-boundaries  ; Request phrase structure
   :thematic-occurrences] ; Request theme locations

Query request (in agent response):

(query-request
  :type melodic-content
  :instruments [oboe-1]
  :measures #uuid "..." #uuid "..."
  :reason "Need oboe line to avoid doubling")

The orchestrator may grant or deny queries based on scope and permissions.

Constraints

Constraints specify rules that generated content must satisfy:

:constraints
  ((range clarinet-bb E3 C7)           ; Notes within instrument range
   (avoid parallel-fifths violin-1)    ; Voice-leading rule
   (prefer chord-tones downbeats))     ; Style preference

Constraint Types

Type	Syntax	Description
Range	`(range <instrument> <low> <high>)`	Notes within range
Avoid	`(avoid <violation> <ref-part>?)`	Prevent voice-leading errors
Prefer	`(prefer <feature> <location>)`	Style preferences
Density	`(note-density <min> <max>)`	Notes per measure

Constraint violations are caught in the musical rules validation stage.

Overview

MRS-S Format

Agent Workflows

Model & Validation

Working Set Envelope

Design Principles

Envelope Structure

Envelope Fields

Required Fields

Scope Specification

Permission Fields

Optional Fields

Content Self-Containment

Task-Adaptive Context Views

View Types

View Selection by Task

Boundary-Crossing Spans

Boundary Rules

Available Queries

Constraints

Constraint Types

​Design Principles

​Envelope Structure

​Envelope Fields

​Required Fields

​Scope Specification

​Permission Fields

​Optional Fields

​Content Self-Containment

​Task-Adaptive Context Views

​View Types

​View Selection by Task

​Boundary-Crossing Spans

​Boundary Rules

​Available Queries

​Constraints

​Constraint Types

Design Principles

Envelope Structure

Envelope Fields

Required Fields

Scope Specification

Permission Fields

Optional Fields

Content Self-Containment

Task-Adaptive Context Views

View Types

View Selection by Task

Boundary-Crossing Spans

Boundary Rules

Available Queries

Constraints

Constraint Types