All MIDI keyboards work with Soundtrap on Mac, Windows and Chromebook. If your keyboard has a USB MIDI output, connect it directly to your computer via a USB cable. If your keyboard only has old school 5-pin MIDI connectors you will need a separate MIDI interface to connect it to your computer.
Here are some examples of USB MIDI keyboards that work great with Soundtrap:
And here are some examples of MIDI interfaces if you want to connect a keyboard with old school MIDI connectors:
For those who use MIDI controllers such as electronic drum kits or push tablets, Soundtrap's note mapping might not correspond with the mapping of your controller. Unfortunately there’s no way to customize the mapping at the moment.