Disable startup music
In case anyone is tired of the boot-up music, it can be disabled. The file is called PowerOn.ogg and is located in system/media/audio/ui. I used Root Browser to get at it. To disable it, rename it. I renamed by adding ".old" (no quotes) at the end of the name. To put it back, remove the name addition from the file. This worked on the SM-T320 and the SM-T520.
Root browser is a powerful tool. If you mess up, it's on you.