Spray Paint Tool

The Spray Paint Tool , the third icon from the left at the top of the Graphic Editor window, is a unique algorithmic composition tool. Use it for everything from overcoming writer’s block to building percussive parts, randomly triggering samples, creating melodic lines across chord changes, generating aleatoric music, or anything else you might dream up. The Spray Paint Tool can be configured to create MIDI data within the constraints of musical scales, pitch intervals, chord changes, note start times, durations, and velocity ranges.

To use the Spray Paint Tool:

  1. In the Graphic Editor window, double-click the Spray Paint Tool icon.

The Spray Note Tool dialog box appears.

  1. Choose the options for spray painting that you want (see below).

  2. The Single-click or drag the mouse within the Notes or Drums displays of the Graphic Editor window to 'spray paint' new notes into a track according to the constraints set in the Spray Note Tool dialog box.

For example, you could use the Spray Paint Tool to build original drum patterns from scratch. Just spray paint the drum data into the Drum Grid display; if you want, Option-click on any Drum Name to transpose it to any other drum timbre; then try applying different grooves via Metro's Groove Quantize feature. You will be amazed at how fast you can generate some great-sounding drum parts this way.

Here are the options available in the Spray Note Tool dialog box:

  • Click the Constrain pitch to the scale of button and choose a Scale from the popup menu if you want the spray painted notes to be confined to a particular scale. Open the scale popup menu by clicking the scale name that is located in the Constrain pitch to field.


  • Click the Constrain pitch to Chord changes in markers button if you want the spray painting of notes to be constrained to Chord Changes entered in the Markers row.

  • Click the Quantize button if you want the spray painting of notes to be quantized to your specifications. (See below for Methods.)

  • Choose the Fast, Medium, or Slow speed to affect the density of notes that will be sprayed.


  • Auto Advance, when checked, instructs the Spray Paint Tool to generate single note lines. Just click and hold the mouse where you want the line to start; notes will be generated one after another, advancing for as long as the mouse is held down.

  • Allow Error is a way to specify the range of clocks that will be allowed after the Quantization Method is performed. Allow Error produces a less mechanical sounding performance.

  • Maximum Time Interval specifies the maximum time from the current cursor position to where a spray painted note can be generated. Maximum Time Interval is specified in clocks.

  • Maximum Pitch Interval specifies the maximum pitch from the Current Cursor Position to where a spray painted note can be generated. Maximum Pitch Interval is specified in steps of the specified scale. For example, the Chromatic scale equals semitones.

  • Duration and Velocity Ranges allow you to specify the minimum and maximum values to be applied to newly generated notes. You can also apply the Graphic Editor's Duration Value (specified in the Notes pop-up menu or Note Value field) by selecting the Use note duration from graphic editor radio button.

  • Select the Quantize checkbox to enable the quantization of notes generated by the Spray Paint Tool. Specify a quantization routine by clicking the Methods button to open the Spray Note Tool Quantize dialog box.

  • Choosing the Quantize to step entry duration button will quantize the Spray Paint Tool to the step entry duration value specified in the Graphic Editor window. Otherwise, you can specify four different possible durations to which the Spray Paint Tool will quantize. The four quantization values are to be assigned various weights. Weights determine the probability of which quantization routine will be selected. If the total of all four weights adds up to more than 100%, only the first weights (added from left to right) adding up to 100% will be considered.

See Also:

Tips for using Note Spray

Spray Paint Tool