The Midas page above was missing the part about the reeds when I looked.

Click for one of the versions of The Two Sisters (a speaking harp made from the murdered girl's body).

Lloyd Alexander published (1967) a charming children's book called The Truthful Harp: it breaks a string every time the (Welsh-sounding) would-be-bard takes liberties with facts. Comically done. (One of the first stories in what became a rather massive series.)

Legends from Tuva (speaking through a stringed instrument and a jaw harp): http://www.kiravan.com/MTALLIS.htm

I can't recall a searchable phrase, but I believe that a prophetic drum made from the skin of a loved one occurs in myths from various continents.

Literal "Talking Drums" at http://www.smithsonianmag.si.edu/smithsonian/issues00/jun00/mall_jun00.html:
"Batá drums imitate the tonal language of Yoruba. Any Yoruba syllable has one of three tones, in a fixed relationship with each other, and the batá imitates them."