Unable to run a shell script as a systemd service

I have a small script to transform midi input notes to media functions (volume up, next song, etc). It looks like this:

#!/bin/bash
aseqdump -p "CMD MM-1" | \
while IFS=" ," read src ev1 ev2 ch label1 data1 label2 data2 rest; do
    case "$ev1 $ev2 $data1" in
        "Note on 32" ) xdotool key XF86AudioRaiseVolume ;;
        "Note on 31" ) xdotool key XF86AudioLowerVolume ;;
        "Note on 51" ) xdotool key XF86AudioMute ;;
        "Note on 28" ) xdotool key XF86AudioPrev ;;
        "Note on 29" ) xdotool key XF86AudioNext ;;
        "Note on 50" ) xdotool key XF86AudioPlay ;;
    esac
done

I can launch it from the terminal and it remains unable to receive commands until I press ctrl+c. So far so good. My question is, how can I use this script as a service so that I don't have to worry about it being in a visible terminal and running on reboot?

I have a service file in /etc/systemd/system/ with the following content:

[Unit]
Description=My Shell Script for Sync

[Service]
ExecStart=/bin/bash /usr/bin/midi2keys.sh

[Install]
WantedBy=multi-user.target

To survive the reboot you should save your script in

cd /opt/systemd/ then sudo chmod a+x YOURSCRIPTFILENAME

then create a service like

sudo touch /etc/systemd/system/YOURSERVICENAME.service

Then Edit the file by typing sudo nano /etc/systemd/system/YOURSERVICENAME.service and then typing in :

[Unit]
Description=My Shell Script for Sync

[Service]
ExecStart=/bin/bash /usr/bin/midi2keys.sh

[Install]
WantedBy=multi-user.target

then Ctrl + X to exit , Y to save and enter to write file.

Now to install the service and ensure it loads at boot time type:

systemctl daemon-reload
systemctl enable YOURSERVICENAME.service

reboot the machine.