This Duck is a plugin that makes it easy to perform ducking (also known as the sidechain effect). Ducking is a mixing technique that makes one sound "quieter" to make space for another sound. (For example, ducking a bassline to make space for a kick drum). This Duck is an excellent plugin that realizes the important concept of ducking with a simple UI and easy operability. With a graphical UI that allows you to check the envelope at a glance, you can easily shape the volume of the sound. This envelope is triggered in one of the following ways: ・Constant repeat rate ・MIDI ・External audio signal input to the plugin's sidechain (unusual for this type of plugin) The function triggered by "external audio signal input to the plugin's sidechain" in particular should be useful for breakbeat music producers. It also features a "2-band split mode" that allows for quick and effective mix adjustments in music production. This allows you to control the amount of ducking for high and low frequencies separately. Ducking, or sidechain compression, is one of the most crucial effects in modern music (from classic house to modern EDM). Whether you're making a pumping house track or a broken beat, Duck will work its magic in seconds. With Duck, you can easily design "repeating custom volume shapes" at the speed and depth you choose, or find new and exciting effects using one of the 58 presets. In addition to sidechain compression, Duck can be used for trance gating, tremolo, and other volume effects. You can also enable split band mode and adjust low and high frequencies separately, giving you more granular control over your sound. Also, Duck can be triggered by audio or MIDI notes from the sidechain input, making it easier than ever for hip-hop and bass music producers.