of course you could, using second hand stuff. I haven't tried pi 4 yet but anything with a modern ish i5 and mic input should suffice (Gigabyte Brix, Lenovo Thi

of course you could, using second hand stuff. I haven't tried pi 4 yet but anything with a modern ish i5 and mic input should suffice (Gigabyte Brix, Lenovo Thinkcentre Mini), can be picked up cheaply and run both Windows and linux well. look for some USB foot pedals as they are cheap, low latency switches which act like a keyboard so you can assign pretty much anything to them within the OS. they come in singles or triples. as for an amp, studio monitors can suffice (I use a pair of Behringer MS20s which cost <$100) since playing live they will be miced up and/or routed directly to the venue's PA anyway. it might be janky, less durable and less reliable but it's great fun and certainly not impossible