This is a modified version that works with the CC: Tweaked mod. It can use commands on a Command Computer or Speakers on normal Computers. (No other mods required)

• Updated for CC: Tweaked using 1.16+ commands or CC: Tweaked speakers
• Plays NBS (Note Block Studio) files
  • wave-amp will automatically load all .nbs files on your CC: Tweaked computer.
• Cool UI
• Music visualiser
• Different play modes (normal, stop, repeat, shuffle)
• Custom themes
• Flexibility through command-line arguments
• Compatability with the newer Open Note Block Studio

• Either place a command computer or a advanced computer
• If using command computers no further steps are required
• If using non-command computers you need at least one speaker connected to your computer
  • You can connect them via network cables or just place them next to the computer

• wave-amp2 pastebin get nKyXwuuf wave-amp2

• dark theme pastebin get HYrhP1yN darktheme
• red theme pastebin get EP0vBAa5 redtheme

• pastebin get cUYTGbpb bbpack
• bbpack get CYRmLz78 Songs

Thanks to Bomb Bloke (Original Comment)

wave-amp2 uses nbs files for music storage. You can create your own songs using Note Block Studio or the newer open-source version Open Note Block Studio

With Note Block Studio you can convert midi versions of your favourite songs to nbs files ans play them in-game.

wave-amp -h

-l                      lists all outputs connected to the computer.
-c <config file>        loads the parameters from a file. parameters are separated by newlines.
-t <theme file>         loads the theme from a file.
-f <filter[:second]>    sets the note filter for the outputs.
examples:
-f 10111                sets the filter for all outputs to remove the bass instrument.
-f 10011:01100          sets the filter so the bass and basedrum instruments only come out of the second output
-v <volume[:second]>    sets the volume for the outputs.
--nrm --stp --rep --shf sets the play mode.
--noui --noinput        disables the ui/keyboard input
--exit                  to reboot the system after a song played

You can use this script on monitors with the monitor command: monitor <monitor_name> wave-amp2