Once you've found a script, like the one hinted at by our keyword, here's the general process to run it:

Verify if the game has custom script protections or if the audio ID you are using has been deleted/copyright-blocked by Roblox.

A "boombox script" goes far beyond simply playing music. It can grant you access to paid boombox gear for free or create a custom music player. Scripts like [ FE ] - Get Free Boombox - Be invisible! - Save 78 robux! explicitly advertise the ability to obtain free gear. More advanced versions provide a fully customizable GUI (graphical user interface) for scrolling through and playing any song from the Roblox library, with features that automatically stop the music when the boombox is unequipped.