Overview:
This one-block creation I made enables you to listen to music in Minecraft in a new way! It's a fully modular jukebox that plays music with the press of a button.
The music is encoded in blocks, and a cursor plays the song by running through the lines of "code" (much like a punchcard).

Features:
-Fully expandable. Choose the songs you like the most and install them easily
-Listen to music everywhere, with the press of a button
-Don't worry about lag. This contraption uses almost no entities to work, so it should be functional on most computers :)
-Song included. This creation comes with a preview song to test the system, so you don't have to install anything else.

Compatibility: Minecraft 1.11+

How to get it (you must be in a world where you can use commands)
-Get yourself a command block, by opening the chat and typing /give @p command_block
-Place it down.
-Open it and paste the code you find at this link
-Click on "Needs redstone" to change it to "Always active"
-Click on "Done" and wait a few seconds
-Open the command block again and paste the code you find at this other link
-Click on "Needs redstone" once again, and then on done
-Enjoy!

This build took me a lot of time, so I would really appreciate some feedback and I would love to hear suggestions on what music I should implement first...

Known issues:
-When first playing the songs, it takes a few tries for them to play at normal speed. After a few tries, though, it will sort itself out.