▁left ▁hand , ▁used ▁by ▁James ▁P . ▁Johnson , ▁F ats ▁W aller , ▁and ▁Earl ▁H ines , ▁used ▁a ▁bass ▁note ▁on ▁the ▁first ▁and ▁third ▁be ats , ▁followed ▁by ▁a ▁mid - range ▁ch ord ▁to ▁emphas ize ▁the ▁second ▁and ▁fourth ▁be ats . ▁ ▁The ▁lead - in ▁be ats ▁were ▁not ▁aud ible , ▁but ▁expressed ▁in ▁the ▁motion ▁of ▁the ▁left ▁arm . ▁ ▁Sw ing ▁bass ▁piano ▁also ▁put ▁the ▁first ▁and ▁third ▁be ats ▁a ▁role ▁anticip atory ▁to ▁the ▁emphas ized ▁second ▁and ▁fourth ▁be ats ▁in ▁two - be at ▁figures . ▁▁ ▁As ▁swing ▁music ▁developed , ▁the ▁role ▁of ▁the ▁piano ▁in ▁the ▁ensemble ▁changed ▁to ▁emphas ize ▁acc ents ▁and ▁fills ; ▁these ▁were ▁often ▁played ▁on ▁the ▁lead - in ▁to ▁the ▁main ▁beat , ▁adding ▁a ▁p unch ▁to ▁the ▁rh ythm . ▁ ▁Count ▁Bas ie ' s ▁style ▁was ▁sparse , ▁played ▁as ▁accompan iment ▁to ▁the ▁horn ▁sections ▁and ▁solo ists . ▁ ▁The ▁bass ▁and ▁sn are ▁drums ▁started ▁the ▁swing ▁era ▁as ▁the ▁main ▁time keep ers , ▁with ▁the ▁sn are ▁usually ▁used ▁for ▁either ▁lead - ins ▁or ▁emphas is ▁on ▁the ▁second ▁and ▁fourth ▁be ats . ▁ ▁It ▁was ▁soon ▁found ▁that ▁the ▁high - hat ▁c ym bal ▁could ▁add ▁a ▁new ▁dimension ▁to ▁the ▁swing ▁expressed ▁by ▁the ▁drum ▁k it ▁when ▁played ▁in ▁a ▁two - be at ▁" ti - t sh