▁a ▁performance ▁practice , ▁mainly ▁from ▁the ▁Bar o que ▁and ▁Class ical ▁music ▁er as , ▁in ▁which ▁some ▁notes ▁with ▁equal ▁written ▁time ▁values ▁are ▁performed ▁with ▁une qual ▁dur ations , ▁usually ▁as ▁altern ating ▁long ▁and ▁short . ▁The ▁practice ▁was ▁especially ▁pre val ent ▁in ▁France ▁in ▁the ▁ 1 7 th ▁and ▁ 1 8 th ▁centuries , ▁with ▁appearances ▁in ▁other ▁European ▁countries ▁at ▁the ▁same ▁time ; ▁and ▁it ▁re app eared ▁as ▁the ▁standard ▁performance ▁practice ▁in ▁the ▁ 2 0 th ▁century ▁in ▁jazz . ▁ ▁History ▁ ▁Pre - mod ern ▁era ▁ ▁The ▁practice ▁of ▁not ating ▁pairs ▁of ▁une qual ▁note ▁lengths ▁as ▁pairs ▁with ▁equal ▁not ated ▁value ▁may ▁go ▁as ▁far ▁back ▁as ▁the ▁earliest ▁music ▁of ▁the ▁Middle ▁A ges ; ▁indeed ▁some ▁sch ol ars ▁believe ▁that ▁some ▁plain chant ▁of ▁the ▁Roman ▁Catholic ▁Church , ▁including ▁Amb ros ian ▁h ym ns , ▁may ▁have ▁been ▁performed ▁as ▁altern ating ▁long ▁and ▁short ▁notes . ▁This ▁interpretation ▁is ▁based ▁on ▁a ▁passage ▁in ▁Saint ▁August ine ▁where ▁he ▁refers ▁to ▁the ▁Amb ros ian ▁h ym ns ▁as ▁being ▁in ▁t ria ▁tempor um ▁( in ▁three ▁be ats ); ▁e . g . ▁a ▁passage ▁rendered ▁on ▁the ▁page ▁( by ▁a ▁later ▁trans cri ber ) ▁as ▁a ▁string ▁of ▁notes ▁of ▁equal ▁note ▁value ▁would ▁be ▁performed ▁as ▁half ▁note , ▁quarter ▁note , ▁half ▁note , ▁quarter ▁note , ▁and ▁so