I know about connecting digital pianos (MIDIs) to a laptop for use in logic. My question is concerning a standard normal acoustic piano. My baby grand has a silent piano Yamaha system attached to it so I can practice with headphones. It has a headphone input - if I buy a 3.5mm aux jack to usb c cable, would I be able to record using my piano in logic?
Based on your comment (Bosendorfer piano, Yamaha silent system), if you record your piano from the headphone jack you will not be recording your actual piano sound but a digital piano sample (although I’m sure a very good one) that Yamaha has built into its silent piano.
This question is borderline off topic (gear recommendation) but I will try and provide some useful information and options.
If you want to record the real acoustic sound of your piano in stereo then you will need two mics (or a stereo mic) and an audio interface with two XLR inputs, or a stereo mic with a USB output. Companies like Focusrite, Presonus, Mackie and many others make interfaces starting at a little over $100 and go way up from there.
If you are fine with just recording the Yamaha digital sample then there are some options. Some older Macs actually have a microphone/line input. Some not-so-old Macs have a two function jack that works either as a headphone or a mic/line in. An internet search of the year and model of your Mac should help you find out if yours has this feature. If yours is one of these then all you need is a stereo cable to send a signal to the computer. Keep in mind that this will not give you the best sound quality but may be fine for your purposes.
If it doesn’t have the mic/line in feature then you will need some type of interface and adapter plugs or cables to record. Check to see if the headphone out is the only audio output on your Yamaha system. If there is another output make a note of it and call a company like Sweetwater. They can steer you in the right direction as far as exactly what is required for your specific computer and give you options covering different budgets. Good luck!