Flashing wireless lights and/or wireless music box???

Anyone come across a battery operated music box small enough to add to my knitted Christmas jumpers? Possibly playing jingle bells or something Christmassy?

I've seen some which use a pull string to make work, but wondered if there was something more modern out there?

Also I know of battery operated lights for craft use, but the ones I've seen aren't flashing or turn off-able, if you see what I mean!!

Thanks