How does Rando know the BPM and key of my samples?

In two passes.

First, filenames and folder paths. This is near-instant, so your samples are usable the moment they're added. A file called Loop_124bpm_Amin.wav gives Rando the tempo and key without opening the audio at all.

Then AI scanning, in the background. Rando analyses the audio itself to work out BPM, tonality, key and chord, and instrument type properly. This pass is slower, but it catches everything filenames can't — so a folder of files called audio_01.wav through audio_99.wav still ends up correctly sorted.

If you've just added a large library and the BPM or key looks wrong, give it a moment. The background pass is still catching up, and the data will improve on its own.

Is anything sent anywhere?

No. All of it happens locally on your own machine. Your sample library never leaves your computer, and nothing about it is sent to us or to anyone else.

Where AI scanning is available

On Windows and on Apple Silicon Macs. It isn't available on Intel Macs — a limitation of Apple's model encryption on Intel hardware — so you won't see the Advanced Sample Analysis option in Preferences there.

On an Intel Mac your library is still categorised from filenames and folder paths, which is how most commercial sample packs are labelled anyway.

Turning it off

Preferences → Advanced Sample Analysis. Switching it back on rescans anything you added while it was off.