#Install
sudo apt install midge

#example file
http://www.undef.org.uk/code/midge/dont_fear_the_reaper.mg

#script for creating random music
#!/bin/bash

t=( a b c d e f g)
notes=$(for i in {1..50};do NUMBER=$[ ( $RANDOM % 6 )  + 1 ];echo "${t[$NUMBER]}";done|tr "\n" " ")

cat > tmp.mg << EOF
@head {
    \$tempo 240
    \$time_sig 4/4
    \$title "song"
    \$resolution 960
}
@body {

    @channel 1 "1-Track" {
   	 \$attack 64
   	 \$decay 0
   	 /l4/c6 $notes
    }

    @channel 2 "2-Track" {
   	 \$attack 64
   	 \$decay 0
   	 /l4/c4 $notes
    }
}
midge source written to 2-Track_1-1.mg
EOF

midge tmp.mg
timidity tmp.mid