Many wedding and ceremony photographers are used to recording with one device, only recording microphone sound, not recording live background music. What is the name of this device?
Recording pen, chest microphone, pickup microphone. If it were me, I wouldn't need these. Just use the 1 long audio cable to receive the audio input from the camera from the live mixer. Note that some mixers have 6.5 ports, and some have a muzzle, so make a short converter or buy a converter. The background music upstairs said it was added later.