Thanks to Cesare for all these tips:

ALSA should support your USB MIDI Keyboard already.
To Check - insert the keyboard and reboot

From the terminal type:

cat /proc/asound/cards

This should list all your devices and their number

Then - using a MIDI ,csd, such as the one attached, you can type the following commandline:

csound -+rtmidi=alsa --midi-device=hw:1,0 -+rtaudio=alsa -odac MIDI_fof.csd

Note: you might need to change hw:1,0 to hw:0,0 on your system
Also Note: if you want to display the output of CsoundXO in the terminal window, add the following to the commandline:

csound -+rtmidi=alsa --midi-device=hw:1,0 -+rtaudio=alsa -odac -O stdout MIDI_fof.csd