There are several ways to add a new channel in FL Studio's pattern window. These can be samples, loops, FL Studio Generators like FL Slicer, FL Keys, etc or even thrid party VST instruments.
For the sake of this tutorial lets split the lesson depending on what you are trying to add. Well split it by samples and instruments.
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Category: FL Studio | Sounds | Tutorials | VST Instruments
Tags: pattern, samples, plugins, tutorial fl studio