▁S ui ▁and ▁Tang ▁dynast ies ▁mostly ▁for ▁court ▁music . ▁ ▁Const ruction ▁and ▁Design ▁ ▁St ones ▁in ▁the ▁ancient ▁sets ▁are ▁( like ▁the ▁b ells ) ▁usually ▁of ▁similar ▁thick ness ▁but ▁of ▁grad ed ▁size . ▁It ▁consists ▁of ▁ 1 6 ▁iron , ▁bronze ▁or ▁j ew el ▁tun ed ▁rect angular ▁sl abs ▁with ▁ 1 6 ▁different ▁pitch es , ▁laid ▁in ▁a ▁frame ▁in ▁two ▁rows ▁and ▁usually ▁constructed ▁in ▁L - shape . ▁ ▁The ▁sl abs ▁are ▁struck ▁with ▁a ▁ham mer ▁and ▁played ▁mel od ically . ▁Un like ▁the ▁metal lo phone ▁today , ▁Chinese ▁changed ▁the ▁thick ness ▁of ▁the ▁metal ▁pl ates ▁to ▁get ▁different ▁pitch es . ▁Each ▁of ▁the ▁sl abs ▁is ▁of ▁the ▁same ▁length ▁and ▁width ▁but ▁they ▁are ▁of ▁graduated ▁thick ness , ▁with ▁the ▁th inner ▁sl abs ▁producing ▁lower ▁t ones ▁and ▁the ▁th icker ▁sl abs ▁producing ▁higher ▁t ones . ▁ ▁History ▁ ▁In ▁ancient ▁times , ▁the ▁f ang xi ang ▁was ▁a ▁popular ▁instrument ▁in ▁Chinese ▁court ▁music . ▁It ▁was ▁introduced ▁to ▁Korea , ▁where ▁it ▁is ▁called ▁b ang hy ang ▁( hang ul : ▁ 방 향 ; ▁han ja : ▁ 方 <0xE9> <0x9F> <0xBF> ) ▁and ▁is ▁still ▁used ▁in ▁the ▁court ▁music ▁of ▁Korea . ▁A ▁similar ▁instrument ▁used ▁in ▁Japan ▁is ▁called ▁the ▁h ō ky ō ▁( kan ji : ▁ 方 <0xE9> <0x9F> <0xBF> ). ▁ ▁The ▁first