▁Background ▁and ▁composition ▁" What ▁You ▁Don ' t ▁Know " ▁features ▁a ▁prominent ▁horn ▁section ▁accomp any ing ▁the ▁sing ers , ▁and ▁there ▁is ▁a ▁guitar ▁solo ▁between ▁the ▁second ▁and ▁third ▁vers es . ▁Although ▁the ▁group ▁continued ▁to ▁have ▁success ▁on ▁the ▁dance ▁charts , ▁this ▁was ▁one ▁of ▁the ▁final ▁Ex pos é ▁pop ▁hits ▁featuring ▁a ▁beat , ▁with ▁which ▁they ▁had ▁become ▁associated ▁from ▁most ▁of ▁the ▁singles ▁off ▁their ▁previous ▁album , ▁Ex pos ure ▁( 1 9 8 7 ). ▁Many ▁of ▁the ▁singles ▁released ▁by ▁the ▁group ▁from ▁this ▁point ▁on ▁were ▁mid - tem po ▁or ▁ball ads . ▁ ▁Music ▁video ▁The ▁accomp any ing ▁music ▁video ▁for ▁" What ▁You ▁Don ' t ▁Know " ▁features ▁the ▁sing ers ▁re he ars ing ▁with ▁a ▁band ▁on ▁stage , ▁then ▁near ▁the ▁end ▁of ▁the ▁music ▁video ▁the ▁girls ▁r ush ▁back ▁to ▁be ▁with ▁their ▁respective ▁boy fri ends . ▁ ▁Track ▁listing ▁ ▁US ▁ 7 " ▁vin yl ▁single ▁( Ar ista ▁Records ▁AS 1 - 9 8 3 6 ) ▁A ▁" What ▁You ▁Don ' t ▁Know " ▁– ▁ 3 : 5 8 ▁B ▁" W alk ▁Al ong ▁with ▁Me " ▁– ▁ 3 : 4 9 ▁ ▁US ▁ 1 2 " ▁vin yl ▁single ▁( Ar ista ▁Records ▁AD 1 - 9 8 3 7 ) ▁A 1 ▁" What ▁You ▁Don ' t ▁Know ▁( At omic ▁Mix )" ▁–