So it's the grandpa judge who gave the violin to white haired woman? I'm confuse :(

i am confusion

Nah, dudes dead now, he was hella old when he gave it to her in her twenties

Yeah he’s dead, that’s how they were able to buy MC his violin in an auction. MC’s violin was crafted together with hers from the same maker, so they’re like a pair. She’s just having flashbacks about when she got her violin, that old dude (now deceased) bought them to keep them until their “rightful/fated” owner showed up. Since their violins are special in that they choose their owner/can only play for them, and would rather perish if they couldn’t find them (which is what happened to MC’s violin in the original time line, it burned to ashes)

The old judge guy is just another famous violinist

now that you've mentioned it, i got shivers. the old man found the owner for the other violin when he's alive but the other violin found it's owner when he's dead. a play of fate, indeed