anchor-framework

name	anchor-framework
description	Strudel composition methodology using a 4-instrument stack with 4-step harmonic instruments and 12-step melody instruments. Anchor points align every 3rd step of the fast instruments with the slow harmonic rhythm. Triggered by "/anchor-framework KEY" (e.g. "/anchor-framework E:minor").

anchor-framework

Build a Strudel composition in the given key using the Anchor Framework System.

Inputs

/anchor-framework KEY

• KEY — the scale to compose in (e.g. E:minor, D:minor, C:major)

Core Structure

Instrument 1: 4 steps  (chord progression, mid-range)
Instrument 2: 4 steps  (harmonizing bass)
Instrument 3: 12 steps (melody — anchors on steps 1, 4, 7, 10)
Instrument 4: 12 steps (counter-melody — anchors on steps 1, 4, 7, 10)

Because all instruments share the same cycle, instruments 3 and 4 play three times as fast as instruments 1 and 2. Every 3rd step of instruments 3 and 4 (steps 1, 4, 7, 10) falls on the same beat as a step in instruments 1 and 2 — these are the anchor points where all four voices must harmonize.

Step 0 — Harmonic Foundation (start here)

Build the initial stack using piano for all instruments so harmony is easy to hear.

• Instruments 1 & 2: choose notes from chords in the key (they harmonize with each other)
• Instruments 3 & 4: place anchor notes on steps 1, 4, 7, 10 that harmonize with instruments 1 & 2; fill all other steps with ~

const g_scale = "E:minor"

const step0 = stack(
    n("0 2 1 3").scale(g_scale).sound("piano").gain(.6),
    n("-7 -5 -6 -4").scale(g_scale).sound("piano").gain(.6),
    n("-2 ~ ~ 4 ~ ~ 3 ~ ~ 5 ~ ~").scale(g_scale).sound("piano").gain(.6),
    n("7 ~ ~ 7 ~ ~ 5 ~ ~ 3 ~ ~").scale(g_scale).sound("piano").gain(.8)
)

Step 1 — Instrument Selection

Replace piano with varied timbres. Keep the same notes — only the sounds change.

• Instrument 1: pad or string (e.g. gm_pad_sweep, gm_string_ensemble_1)
• Instrument 2: warm pad or bass (e.g. gm_pad_warm, gm_electric_bass_finger)
• Instrument 3: synth bass or lead (e.g. gm_synth_bass_1)
• Instrument 4: bright synth (e.g. supersaw)

Step 2 — Melodic Development

Fill in the non-anchor steps of instruments 3 and 4 to create flowing melodic lines. Anchor notes must stay the same.

Step 3 — Rhythmic Sophistication (Syncopation)

Apply the /syncopations skill transforms to notes in instruments 3 and 4. Randomly pick a few to apply — do not syncopate every note.

Step 4 — Counter-melody

Fill instrument 4 with a sparse melody. Echo some syncopation patterns from instrument 3. All anchor steps must still harmonize with instruments 1 and 2.

Step 5 — Full Arrangement

• Add syncopation to instruments 1 and 2 as well
• Add reverb: .room(2)
• Add sharpening: .shape(.1)
• Add a percussion pattern using s() with drum sounds (e.g. bd, sd, hh, oh)
• Wrap everything in arrange() to sequence the steps with repeat counts

arrange(
  [2, step0],
  [2, step1],
  [2, step2],
  [2, step3],
  [2, step4],
  [2, step5],
  [10, step6]
).slow(1.6)

Key Strudel Concepts

• stack() — combines multiple instruments playing simultaneously
• n() — scale degree notation (0 = root, negative = below root)
• .scale("E:minor") — constrains all n() values to the chosen scale
• ~ — rest (silence for one step)
• [] — group sub-steps within a single step (used for syncopation)
• .gain() — volume (0–1)
• .room() — reverb amount
• .shape() — soft distortion / sharpening
• arrange([count, pattern], ...) — sequence patterns with repeat counts