The material below is Open Game Content from a 3PP Source
Lyre of Building
Aura moderate transmutation; CL 6th
Slot none; Price 13,000 gp; Weight 5 lbs.
This magical instrument is usually made of gold and inlaid with numerous gems. If the proper chords are struck, a single use of this lyre negates any attacks made against inanimate construction (walls, roof, floor, and so on) within 300 feet. This includes the effects of a horn of blasting, a disintegrate spell, or an attack from a ram or similar siege weapon. The lyre can be used in this way once per day, with the protection lasting for 30 minutes.
The lyre is also useful with respect to building. Once a week, its strings can be strummed so as to produce chords that magically construct buildings, mines, tunnels, ditches, etc. The effect produced in 30 minutes of playing is equal to the work of 100 humans laboring for 3 days. Each hour after the first, a character playing the lyre must make a DC 18 Perform (string instruments) check. If it fails, she must stop and cannot play the lyre again for this purpose until a week has passed.
Requirements Craft Wondrous Item, fabricate; Cost 6,500 gp