i know from personal experience where my son wrote all over tile and walls with a permanent marker (at someone else's house), toothpaste will remove permanent marker without damaging delicate paint or tile, it may work on wood as well. Try it in an inconspicuous spot.

well, at least it's now more precious. it showed the time your lil brother has achieved something. you now have it forever and your 100 year old piano. try to be proud of him. :)

you can get out permanent marker with hairspray.

since when do people young enough to have toddler-age siblings own 100 year old pianos?

have you tried an expo marker those can erase permenant marker

Grrrr, this is why I hate children! Don't be so quick to jump on the "parents'/OP's fault" bandwagon. Kids are capable of pulling off anything and everything within 1 minute. And God forbid you sleep til a decent hour, because your child/sibling will sleep just enough time less that it takes to cause visible destruction (like, idk, a vile haircut... not that I'm speaking from experience or anything). Granted, parents/adults need to do whatever possible to keep children away from markers/scissors/cake/soap/animals/explosives/glue/etc., nothing short of a straight-jacket will stop a child from causing destruction. I vote beating the child within an inch of his life, punishing him a la A Clockwork Orange with classical music, and hoping for the best. ;)

try using a magic eraser it worked on my tables for the same thing

It's a good thing pianos are one of the only instruments that don't get better with age then.

a chance to get a new better piano (:

ahhh he must be the future art designer for piano's but well you could paint it ?