▁as ▁well ▁as ▁Z app ' s ▁debut , ▁pe aking ▁at ▁number ▁two ▁on ▁the ▁Billboard ▁R & B ▁chart , ▁and ▁reaching ▁ 2 5 ▁on ▁The ▁Billboard ▁ 2 0 0 ▁Albums ▁chart . ▁The ▁single ▁" D ance floor ▁( Part ▁I )" ▁pe aked ▁at ▁number ▁one ▁on ▁the ▁R & B ▁singles ▁chart ▁of ▁ 1 9 8 2 . ▁ ▁Z app ▁spawn ed ▁several ▁more ▁albums ▁in ▁close ▁succession , ▁retain ing ▁the ▁s lick ▁electronic ▁style ▁that ▁Z app ▁II ▁had ▁adopted , ▁but ▁with ▁dimin ishing ▁success . ▁Z app ▁III ▁was ▁released ▁in ▁ 1 9 8 3 , ▁and ▁managed ▁to ▁gain ▁a ▁gold ▁cert ification , ▁but ▁pe aked ▁at ▁only ▁ 3 9 ▁on ▁the ▁Billboard ▁ 2 0 0 ▁and ▁nine ▁on ▁the ▁R & B ▁chart . ▁Z app ▁III ' s ▁poor er ▁commercial ▁performance ▁became ▁a ▁sign ▁that ▁the ▁band ' s ▁popular ity ▁and ▁impact ▁were ▁beginning ▁to ▁decl ine ▁toward ▁the ▁mid ▁ 1 9 8 0 s , ▁with ▁post - dis co ▁music ▁falling ▁out ▁of ▁tr end . ▁By ▁the ▁release ▁of ▁The ▁New ▁Z app ▁IV ▁U ▁in ▁October ▁ 1 9 8 5 , ▁the ▁down ward ▁traject ory ▁was ▁evident . ▁The ▁album ▁did ▁not ▁att ain ▁gold ▁status ▁until ▁ 1 9 9 4 , ▁almost ▁a ▁de cade ▁after ▁its ▁initial ▁release . ▁Z app ' s ▁presence ▁f aded ▁further ▁in ▁the ▁latter ▁half