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.

To tell someone to be safe and take care.

expression used on the radio show "weekly record check"
broadcasted on justqualitymusic.com
by Chicago dj and producer Pete Kazimierski.

Means stay tuned, keep listening, do not switch the channel.