A harp might be one of two musical instruments:
Both cost 50 zm (and weigh 30), so price identification does not help.
Wooden will either play "a lilting melody" (which pacifies nymphs) or else it "twangs." If a harp produces "very attractive music" it is a magic harp instead.
A triangular stringed instrument, often Magic. Even when not
Magic, a Harp is surprisingly portable and tough and can be
carried everywhere on the back of the Bard or Harper in all
weathers. A Harp seldom goes out of tune and never warps.
Its strings break only in very rare instances, usually
because the Harper is sulking or crossed in love. This is
just as well as no one seems to make or sell spare strings.
After breakfast was over, the ogre called out: "Wife, wife,
bring me my golden harp." So she brought it and put it on
the table before him. Then he said: "Sing!" and the golden
harp sang most beautifully. And it went on singing till the
ogre fell asleep, and commenced to snore like thunder.
Then Jack lifted up the copper-lid very quietly and got down
like a mouse and crept on hands and knees till he came to the
table, when up he crawled, caught hold of the golden harp and
dashed with it towards the door. But the harp called out
quite loud: "Master! Master!" and the ogre woke up just in
time to see Jack running off with his harp.
by Joseph Jacobs ]