▁and ▁traditional ▁R & B ▁tracks . ▁N iel sen ▁Audio ▁sometimes ▁refers ▁to ▁the ▁format ▁as ▁Urban ▁adult ▁contemporary ▁radio . ▁Billboard ▁created ▁the ▁chart ▁in ▁September ▁ 1 9 9 3 , ▁with ▁the ▁first ▁number ▁one ▁being ▁" An other ▁Sad ▁Love ▁Song " ▁by ▁T oni ▁Bra xt on . ▁ ▁Chart ▁criteria ▁There ▁are ▁thirty ▁positions ▁on ▁this ▁chart ▁and ▁it ▁is ▁sole ly ▁based ▁on ▁radio ▁air play . ▁ 6 5 ▁urban ▁AC ▁radio ▁stations ▁are ▁electron ically ▁monitor ed ▁ 2 4 ▁hours ▁a ▁day , ▁seven ▁days ▁a ▁week ▁by ▁N iel sen ▁Broadcast ▁Data ▁Systems . ▁Songs ▁are ▁ranked ▁based ▁on ▁the ▁number ▁of ▁plays ▁that ▁each ▁song ▁received ▁during ▁that ▁week . ▁ ▁Songs ▁receiving ▁the ▁greatest ▁growth ▁will ▁receive ▁a ▁" bullet ", ▁although ▁there ▁are ▁tracks ▁that ▁will ▁also ▁get ▁bul lets ▁if ▁the ▁loss ▁in ▁det e ctions ▁doesn ' t ▁exceed ▁the ▁percentage ▁of ▁dow nt ime ▁from ▁a ▁monitor ed ▁station . ▁" A ir power " ▁awards ▁are ▁issued ▁to ▁songs ▁that ▁appear ▁on ▁the ▁top ▁ 2 0 ▁of ▁both ▁the ▁air play ▁and ▁audience ▁chart ▁for ▁the ▁first ▁time , ▁while ▁the ▁" gre at est ▁g ainer " ▁award ▁is ▁given ▁to ▁song ▁with ▁the ▁largest ▁increase ▁in ▁det e ctions . ▁A ▁song ▁with ▁six ▁or ▁more ▁sp ins ▁in ▁its ▁first ▁week ▁is ▁awarded ▁an ▁" air play ▁add ". ▁If ▁a ▁song ▁is ▁tied ▁for ▁the ▁most ▁sp ins ▁in