How Control Change Messages Work
The final part, closing out this series of explainers on MIDI
This is the final installment in this three-part fictional dialogue on the fundamentals of MIDI. Last time, we covered all eight types of MIDI messages: Note On, Note Off, Aftertouch, Polyphonic Aftertouch, Pitch Bend, Program Change, Control Change, and System Messages.
This week we’re looking into MIDI CC Messages in a bit more detail. These are flexible tools that allow you to control various parameters on synths or samplers. Let’s delve back into our fictional dialogue between Toni Able and Roland Prophet, to round of this series on the fundamentals of MIDI.
Toni: I found our last conversation really enlightening. I learned a lot about MIDI messages, but there was one type we didn’t cover in much detail. Can you remind me of the name?
Roland: I’m glad to hear you found it helpful. Next to audio, MIDI is the most fundamental data type in any DAW, so it’s good to understand the basics. You’re right—we should cover one more message type in a bit of detail: CC.
Toni: Nice abbreviation. What does CC stand for, and what does it do?
Roland: CC stands for Control Change. This message type relates to MIDI controllers, which let you direct MIDI. Think of all the knobs, buttons, sliders, joysticks, pads, switches, pedals, wheels you might find on a hardware MIDI controller.
Toni: So Control Change means adjusting a dial or fader on a MIDI controller?
Roland: Exactly. Every time you turn a knob, you send a Control Change message to another instrument or your computer. This results in a sound changing over time, like opening a filter’s cutoff frequency.
Toni: Got it. You say Control Change, but I’ve also heard CC messages referred to as Continuous Controller. What’s the correct term?
Roland: There are two types of CCs: Switch Controllers and Continuous Controllers. Switch Controllers, like the Sustain Pedal (CC64) or Portamento (CC65), only turn on or off—they’re binary. Most other CC messages, however, like the modulation wheel (CC1), are Continuous Controllers, meaning they send values between 0 and 127, allowing for more fine-grained control. So technically, Continuous Controllers are a subset of Control Change messages.
Toni: Makes sense. So how do CC messages affect the sound?
Roland: They send a stream of values to a parameter on an instrument. Take CC1, the modulation wheel, as an example. When you turn the wheel, it sends values between 0 and 127 to your computer, which passes them to your synth or sampler. These values can then be used to modulate (hence modulation wheel) any parameter, like filter cutoff, pulse width, or LFO rate. In Logic Pro’s Quick Sampler, CC Messages can determine sample start or end time.
Toni: So MIDI CCs don’t make sound on their own?
Roland: It depends. Most CCs affect the sound indirectly, but some have a direct impact. It helps to group them into three categories.
First, haptic-based controls: These CCs are named after physical interaction, much like aftertouch. Musicians use their bodies to interact with these controls—turning a modulation wheel (CC1), blowing into a breath controller (CC2), or using their foot to operate a pedal (CC4). Today, motion sensors and brainwave-based MIDI devices expand the possibilities of how to control MIDI using your body.
Toni: So these are based on how you physically control the sound. Got it. Keep going.
Roland: Second, effect-based CC messages: These directly shape the sound, similar to how pitch bend changes pitch. Examples include volume (CC7), which controls loudness, and panorama (CC10), which adjusts stereo positioning. Expression (CC11) works like volume but allows finer dynamic control. DAWs often pre-map these, so changing CC7 automatically adjusts track volume.
Toni: Makes sense. What’s the third category?
Roland: Channel mode messages, which have a utility function. These alter an entire MIDI channel rather than tweaking sound parameters. Some, like “All Sound Off” (CC120) and “All Notes Off” (CC123), instantly silence playback. Others, like “Reset All Controllers” (CC121), return all CC values to default.
Toni: So some CCs relate to physical control, some directly shape the sound, and some work at the system level. I’ve noticed that some CCs, like CC3, CC9, and CC14–15, are unassigned. How come?
Roland: Good catch. When MIDI was defined in the early 1980s, the developers left some CC numbers unassigned to allow for future expansion. The idea was that future instruments might add new controls later. However, they were never officially assigned. It’s up to you to decide how to use them.
That’s the key takeaway about Control Change messages. Names like “mod wheel” and “foot control” are just suggestions. Think of them as placeholders. Most CC messages simply send values between 0 and 127, which can be mapped to any control on your MIDI device, and from there to any synth or sampler in your DAW.
Toni: So I don’t have to assign “mod wheel” to the actual mod wheel on my controller?
Roland: Nope! You can assign it to any control you like.
Toni: Interesting. I have a digital piano with three pedals. The right pedal sends CC64 values and sustains notes, and I’d like to keep it that way. But I never use the other two, assigned to CC66 (Sostenuto) and CC67 (Soft Pedal). Can I reassign them?
Roland: It depends on the build of your piano, and how its pedals send CC messages. CC64, CC66, and CC67 are Switch Controllers, meaning they only send on or off messages. But some digital pianos might have pedals that send higher-resolution CC messages with 128 values. You’ll need to check your piano’s documentation.
Toni: That’s great! Maybe I can use one to control filter cutoff with my foot.
Roland: Quite possible! I see you’re getting the hang of CC messages. Use them however they suit you. Except for channel mode messages, which have fixed functions, MIDI’s default CC names are just guidelines. What you assign them to is entirely up to you.
Toni: Thanks! That was really helpful.
Roland: No problem! Always happy to talk about MIDI.