We remind readers to check local laws on this sort of use, especially if recording audio, as some countries and US states may have differing laws on what can be recorded, or even listened to live. This would likely be considered private communications, so recording and sharing would definitely be illegal in most regions.
Recently we also posted about Frugal Radio using an Airspy SDR to listen in on wireless microphones from outside a theatre show.
In one of his latest videos, Rob from the Frugal Radio YouTube channel gives us an interesting alternative way to enjoy a theatre show by demonstrating what he heard on his Airspy SDR when taking it to a Christmas theatre show. In a modern theatre show the actors and actresses typically wear hidden wireless microphones and earpieces, allowing their voices to be amplified and instructions from the producers and directors to be heard. If close enough, these devices can easily be picked up with a SDR and antenna.
In his video Rob explains what sort of radio devices and frequencies are used at the theatre, and despite a few set backs he manages to listen in on these devices from the lobby and from just outside the theatre complex.
Some of the things he hears includes backstage instructions from the directors and production team and of course audio from the performers, including backstage conversations.
2021 SDR Guide Ep 12 : SDR Theatre fail with my AirSpy R2 and RTL-SDR dipole kit