'cuz if you're recording for video you're at 48kHz and if you're recording for music you're at 44.1kHz. And if you bought the gear to do this shit, you get to switch your shit a lot. And it's always this inconvenient. Sampling rate is related to Nyquist Frequency which is kind of like the "half-wave optics" of audio - if you want to reproduce a signal with content at 10kHz, you need to sample it at 20kHz or better in order to accurately reproduce the transients of the waveform. And back when everyone was figuring out digital audio the dorks were "how 'bout 50kHz" or "how 'bout 100kHz" (I had a Yamaha TX-16W whose native sample rate was 50kHz; a Fairlight CMI would go to 100kHz) but the guys who actually had to spec the memory were at "duh think in eights" so that 100kHz Fairlight CMI was 16-bit. So the labs like Philips and Sony were pretty much at "12-24-48kHz, that gives us 4kHz headroom over 20kHz, which everyone thinks is the limits of human hearing, even though it's actually like 16kHz in adults and 18-19kHz in kids but maybe there's some transients over that but good god if we double the sample rate we halve our play time and nobody wants to do Betamax again so... 48." And then Sony said "fuck yeah let's do Betamax again" so when Norio Ohga looked at Philips' recommendation that a CD be about the same size as a cassette tape he said "naah that won't work, it has to hold enough audio for all of Beethoven's Ninth Symphony" and Japan being Japan, and the late '70s being the late '70s, you sure as shit don't tell your CEO he's an idiot you irrevocably shittify digital audio for everyone forever. This is the same Sony who, when given a chance to change audio for the better by standardizing on 24-bit, 96kHz 8-channel audio like literally everyone else said "naaaah, 1Ghz, 1-bit, 'Super' audio CD!" thereby killing high resolution audio in its crib with a whack-ass format war that never even got to the point where Sam Goody carried the shit. And then they put rootkits on all their CDs.