Install aconnectgui by entering the following commands in the terminal:
sudo apt update sudo apt install aconnectgui
graphical ALSA sequencer connection manager
aconnectgui is a graphical utility to connect and disconnect two existing ports on ALSA sequencer system. The ports with the arbitrary subscription permission, such as created by aseqview, can be connected to any (MIDI) device ports. . aconnectgui is a frontend for aconnect, written directly on top of the aconnect source, leaving the original source intact, only adding a couple of ifdefs, and some calls to the gui part. It provides exactly the same functionality, but with a graphical user interface.