Orca's colon operator sends MIDI notes with channel, octave, and note arguments

The special operator : (colon) sends a MIDI note out. Its arguments are: channel (0–f), octave (0–9), note letter (A–G for natural, lowercase a–g for sharp), and optionally velocity. A natural note uses an uppercase letter; the corresponding sharp/flat uses lowercase. For example, :03C sends C3 on channel 0; :03c sends C#3. The colon operator fires immediately on the frame it receives a signal, making the delay operator D the natural pairing to control rhythm. Multiple : operators on the same grid can drive chords or different MIDI channels.

Examples

D8… .:03C → bang every 8 frames, send C on octave 3, channel 0 .:03c → same but C# (lowercase = sharp)

Assessment

Write the Orca operator line that sends a D#4 note on MIDI channel 2 every 4 frames. Explain what each character encodes.