INSTALLATION (RESOURCE PACK WORKS FROM 1.14)
1) Install Boombox plugin - https://builtbybit.com/resources/boombox-portable-music-box.44003/
2) To install the resource pack, open the zip archive.
There are 5 folders (You need to use one of them):
=> Default minecraft resource pack
=> ItemsAdder resource pack
=> Oraxen resource pack
=> Bedrock resource pack
=> Nexo resource pack
Open one of these folders for your system and open .txt file and read manual how to install!

I will try to do better!
What about interacting with an active pocket boombox, type the command /boombox and a menu will open.