Hard for any speaker system (well, within the reach of most mere mortal incomes) to pull off a truly realistic full band sound.
But for single instruments...
My MBL 121 omnis can be remarkable. I have recordings of my son playing sax, my other son playing trombone, me playing acoustic guitar.
When I play these recordings at live sound levels, from just outside the room it can sound remarkably like someone in there playing a real instrument.
I fooled a few people that my son was in that room playing saxophone and they were amazed it was a recording.