Install vkeybd by entering the following commands in the terminal:
sudo apt update sudo apt install vkeybd
Description:
Virtual MIDI Keyboard
This program allows you to use the Linux AWE32 driver, OSS MIDI sequencer, or ALSA MIDI sequencer and provides "virtual" keyboard (the musical type), which can be "played" using the keyboard or mouse under X11.
Homepage: http://www.alsa-project.org/~tiwai/alsa.html
Version: 1:0.1.18d-2.1
Section: universe/sound