▁flat , ▁the ▁interval ▁may ▁be ▁said ▁to ▁be ▁flat ▁given ▁that ▁as ▁a ▁whole ▁it ▁is ▁too ▁narrow ; ▁while ▁if ▁the ▁lower ▁pitch ▁is ▁flat ▁or ▁the ▁upper ▁pitch ▁is ▁sharp , ▁the ▁interval ▁may ▁be ▁said ▁to ▁be ▁sharp ▁given ▁that ▁as ▁a ▁whole ▁it ▁is ▁too ▁wide . ▁Inter val s ▁are ▁convention ally ▁measured ▁from ▁the ▁bottom , ▁as ▁such ▁in ▁an ▁interval ▁that ▁is ▁too ▁wide ▁the ▁upper ▁pitch ▁is ▁thus ▁sharp . ▁In ton ation ▁exists ▁within ▁the ▁context ▁of ▁musical ▁temper ament , ▁of ▁which ▁there ▁are ▁several ▁types . ▁▁ ▁However , ▁the ▁interval ▁itself ▁may ▁be ▁in ▁t une , ▁in ▁relation ▁to ▁itself ▁( i . e . ▁both ▁notes ▁of ▁the ▁interval ▁are ▁in ▁t une ▁in ▁relation ▁to ▁each ▁other ), ▁but ▁flat ▁or ▁sharp ▁as ▁a ▁whole ▁and ▁thus ▁both ▁notes ▁of ▁the ▁interval ▁are ▁out ▁of ▁t une . ▁ ▁Notes ▁within ▁a ▁mel ody ▁can ▁be ▁either ▁sharp ▁or ▁flat , ▁or ▁in ▁t une , ▁in ▁relation ▁to ▁the ▁other ▁notes ▁in ▁the ▁mel ody ▁or ▁other ▁pitch es ▁sound ing ▁at ▁the ▁same ▁time . ▁ ▁Str ings ▁With ▁f ret less ▁string ▁instruments ▁such ▁as ▁viol ins ▁or ▁cell os , ▁in ton ation ▁depends ▁on ▁the ▁exact ▁places ▁the ▁music ian ' s ▁fingers ▁press ▁the ▁strings ▁against ▁the ▁instrument ' s ▁finger board , ▁as ▁well ▁as ▁any ▁pull ▁or ▁push ▁the ▁music ian ▁ex ert s ▁on ▁the ▁string , ▁either