Essentially means 'keep listening to this audio stream'.
Refers to locking your analogue radio to a particular station for extended listening, though in the modern day, it's more likely you're listening to a webcast or internet radio instead.
We've got the freshest beats from the underground just waiting to explode out of your soundsystems, so keep it locked (down (tight)).
Iconic tagline for community radio station RTRFM 92.1, frequently used by presenters during talk breaks. It encourages listeners to not touch the radio dial or turn off the audio stream when 'locked' on RTRFM.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.