Strumboli

Turn your drawing tablet into a MIDI strumming controller

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Add expressive pitch bend to your notes

Pitch Bend

Controls MIDI pitch bend based on tablet input. Pitch bend adds expressive pitch variation, similar to bending strings on a guitar or using a pitch wheel.

Settings

control

Type: string
Default: "tiltXY"
Options: "pressure", "tiltX", "tiltY", "tiltXY", "xaxis", "yaxis"
Description: Which tablet input controls pitch bend

Examples:

{
  "pitchBend": {
    "control": "tiltX"
  }
}

Common mappings:

  • "tiltX" - Left/right tilt
  • "tiltY" - Forward/back tilt
  • "tiltXY" - Combined tilt magnitude
  • "yaxis" - Vertical position

min

Type: float
Default: -1.0
Range: -1.0 to 0
Description: Minimum pitch bend (down)

Examples:

{
  "pitchBend": {
    "min": -0.5
  }
}

-1.0 = full bend down (typically -2 semitones, depends on receiving device).

max

Type: float
Default: 1.0
Range: 0 to 1.0
Description: Maximum pitch bend (up)

Examples:

{
  "pitchBend": {
    "max": 0.5
  }
}

1.0 = full bend up (typically +2 semitones, depends on receiving device).

default

Type: float
Default: 0
Range: Between min and max
Description: Default pitch bend (no bend)

Examples:

{
  "pitchBend": {
    "default": 0
  }
}

Always use 0 for no bend.

curve

Type: float
Default: 4.0
Range: > 0
Description: Response curve shape

Values:

  • 1.0 - Linear (no curve)
  • 2.0 - Gentle curve
  • 3.0 - Moderate curve
  • 4.0 - Steep curve (very sensitive at low end)

Examples:

{
  "pitchBend": {
    "curve": 3.0
  }
}

spread

Type: string
Default: "direct"
Options: "direct", "inverse", "central"
Description: How input maps to output range

Values:

  • "direct" - 0 → min (down), 1 → max (up)
  • "inverse" - 0 → max (up), 1 → min (down)
  • "central" - 0.5 → default (no bend), edges → min/max

Examples:

{
  "pitchBend": {
    "spread": "central"
  }
}

"central" is useful for tilt-based bend where neutral position = no bend.

multiplier

Type: float
Default: 1.0
Range: > 0
Description: Overall scale factor applied to final value

Examples:

{
  "pitchBend": {
    "multiplier": 0.5
  }
}

Configuration Example

{
  "pitchBend": {
    "min": -1.0,
    "max": 1.0,
    "default": 0,
    "multiplier": 1.0,
    "curve": 4.0,
    "spread": "direct",
    "control": "tiltXY"
  }
}

Usage Examples

Subtle Vibrato

{
  "pitchBend": {
    "min": -0.3,
    "max": 0.3,
    "control": "tiltX",
    "curve": 2.0
  }
}

Guitar-Style Bends

{
  "pitchBend": {
    "min": 0,
    "max": 1.0,
    "control": "tiltY",
    "curve": 3.0,
    "spread": "direct"
  }
}

Position-Based Pitch

{
  "pitchBend": {
    "min": -0.5,
    "max": 0.5,
    "control": "yaxis",
    "curve": 1.0,
    "spread": "central"
  }
}

Related Documentation