Create a new song or open an existing file. There are three main ways to disable a channel from the sequencer in Reason. Make sure that your song has multiple channels, or tracks, so that you can hear a difference when testing the methods.
Mute the channel of the track you would like to disable on the mixer located in the rack. This is the first method to disable sound from the channel. When a track is muted from the mixer, you can still see the green, yellow and red gain meter light up next to the fader because the channel is not completely disabled yet, it is only muted. This method shows that the track is still working and is good for quickly testing the difference between having and not having a particular sound in a song.
Deselect the mute button of your chosen track on the mixer and open the sequencer. Find the corresponding track there and hit its mute button. This mute button functions much like the one on the mixer. You can still see gain levels, and though it is only partially disabled, this method also helps to quickly test sounds. The main difference with this method is that when the mixer is muted, MIDI input becomes muted as well, while with the sequencer muted, you have the freedom to play your selected instrument with your song, thus making this method ideal for adding harmonies and keeping melodies from conflicting.
Deselect the mute button in the sequencer and return to your rack. Press the tab key on your computer keyboard, which will flip the rack around. Just like actual hardware, the digital rack in Reason has cables that must be plugged into the correct places in order to function. Thus, the only way to fully disable an instrument's signal from being picked up by any other machines is to unplug the instrument at the source. For example, the NN-XT and Maelstrom are both instrument sources. This has the same effect as unplugging a real instrument.