My concertina and guitar are noted on the 'household effects' policy.
I had the Lachenal concertina valued first -I had to tell the musical-instrument valuer how much it was worth- and the insurance company have photos and serial#s in my file. Along with photos of about 450 LP records, now effectively worthless!
I'll have to take another photo of how many CDs I now have.

Oh. I suppose they are pretty worthless too, today, along with everything else that I own. Everything is outdated the day you buy it, except vintage cars and bricks-and-mortar.