I have been recording sound professionally for nearly 50 years, mostly music, and much of that classical (but "no" is not part of my vocabulary). Video, for me, is a fairly recent addition (20 years), and multi-camera shooting for the last 10 or so. With live performances curtailed by the COVID epidemic, good video with good sound helps both amateur and professional musicians reach a remote audience. I do live concerts and studio sessions, as well as interviews and presentations, each with unique requirements. I typically use 4 microphones, 2 for space and 2 for details, but up to 26 for large ensembles in session. There are whole books on recording techniques, audio and video, but seldom both together. Ask any two engineers how to mic a piano or drum set, you will get 5 answers. For starters, I'd like to share things I have learned not found in books. Sound Checks are Important! Digital recording does not tolerate overloads. Set the faders at zero, and set the trim (pre-fader) so that the meters peak at about -20 dB. Peak levels in a performance can exceed that by 12 dB or more. On the other hand, the S/N ratio of digital is so large, you can lift very low levels without excessive noise, other than that present in the room Once the input levels are set properly, you can mix and balance the tracks with the faders for a live production, front-of-house (FOH) or monitoring. Record the pre-fader signals, with each microphone on a separate track. That way if you don't like the live mix, you can change it later. Once the recording begins, don't change the trim levels unless you are getting overloads. It's very hard to track trim changes when mixing in post. Start recording early (at least 15 minutes) and end late (e.g., when the last note dies away, or the audience stops clapping) Leave the recording run continuously for concerts and in session. It's disruptive for the talent to have to ask "are we running" in session, and you may miss something important. Punching in for each take is a relic of recording with tape (or film). With tape, you had 60-90 minutes on a reel, and you had to change reels early to avoid running out. With digital, you can record 50 hours of 8-channel music on a 128 GB card. In lieu of starting and stopping, take notes and log the time code at the start of each take. It's much easier to locate the takes using a non-linear-editor (NLE) from notes (or visually) than to keep track of dozens of short clips. That's true for both audio and video. Synchronizing the video and audio can be done several ways. The best way is to record the mix directly in the video, but is often not practical, for issues of distance and mobility. The professional way is to record the same time code on each device. This can be done wired, wirelessly, or by jamming the same time code on each device before starting. With modern cameras and recorders, jamming is good enough for a day's production. The cheapest way (one which I generally use) is to align the camera's sound track and the recorded sound using an NLE, visually and audibly (listen for phasing or echoes). Professional NLE software can automatically align time codes or even audio patterns. The latter can take a very long time, with a high failure rate. Don't use it if you are reluctant to buy green bananas. You have to resync each time either the video or audio stream is interrupted. That's another reason to keep them running.