UE ' s ▁music . ▁Lee ▁asked ▁band mate ▁Jung ▁Y ong - h wa ▁to ▁compose ▁a ▁song ▁for ▁the ▁album , ▁which ▁did ▁not ▁come ▁to ▁f ru ition ▁due ▁to ▁Jung ' s ▁film ing ▁schedule . ▁ ▁The ▁lead ▁single ▁for ▁Spark light ▁Night ▁was ▁determined ▁by ▁the ▁record ▁label ▁via ▁voting ▁between ▁two ▁songs ; ▁" M oon light ▁Sw ing " ▁was ▁ultimately ▁selected . ▁ ▁Music ▁structure ▁De aling ▁with ▁et ernal ▁love , ▁" M oon light ▁Sw ing " ▁is ▁a ▁swing ▁music ▁song ▁which ▁incorpor ates ▁elements ▁of ▁big ▁band ▁and ▁em its ▁a ▁" f air y ▁tale - like " ▁atmosphere . ▁Initial ly ▁a ▁song ▁about ▁remaining ▁" p ure ▁and ▁honest ▁like ▁Peter ▁Pan ", ▁Lee ▁made ▁the ▁decision ▁to ▁change ▁" M oon light ▁Sw ing " ▁into ▁a ▁love ▁song ▁in ▁order ▁to ▁create ▁a ▁more ▁rel atable ▁track . ▁ ▁Release ▁and ▁promotion ▁Spark ling ▁Night ▁was ▁announced ▁as ▁Lee ' s ▁debut ▁Japanese - language ▁studio ▁album ▁on ▁June ▁ 8 , ▁ 2 0 1 6 , ▁with ▁a ▁release ▁date ▁of ▁July ▁ 2 7 . ▁Upon ▁the ▁announ cement ▁of ▁the ▁album , ▁a ▁" special " ▁website ▁was ▁introduced ▁where ▁further ▁information ▁would ▁be ▁revealed . ▁A ▁ 2 0 - second ▁preview ▁of ▁the ▁music ▁video ▁for ▁" M oon light ▁Sw ing " ▁was ▁uploaded ▁on ▁Lee ' s ▁Inst agram ▁account ▁on ▁June ▁ 1 7 , ▁