chant ing . ▁In ▁quarter - chant ing ▁( which ▁is ▁more ▁true ▁to ▁the ▁structure ▁of ▁the ▁Heb rew ▁poetry ), ▁the ▁side ▁that ▁starts ▁( us ually ▁dec ani ) ▁sing ▁the ▁first ▁quarter ▁of ▁the ▁chant ▁( and ▁thus ▁the ▁first ▁half ▁of ▁the ▁verse ). ▁The ▁side ▁that ▁did ▁not ▁start ▁( us ually ▁cant oris ) ▁then ▁sing ▁the ▁second ▁quarter ▁of ▁the ▁chant ▁( and ▁thus ▁the ▁second ▁half ▁of ▁the ▁verse ). ▁This ▁sequence ▁then ▁repe ats . ▁In ▁half - chant ing ▁( which ▁is ▁more ▁true ▁to ▁anti ph onal ▁singing ▁in ▁the ▁Greg or ian ▁style ), ▁dec ani ▁sing ▁the ▁first ▁two ▁qu arters ▁of ▁the ▁chant , ▁and ▁cant oris ▁the ▁next ▁two ▁qu arters ▁( so ▁that ▁each ▁half - cho ir ▁s ings ▁a ▁whole ▁verse ▁at ▁a ▁time ). ▁ ▁With ▁anti ph onal ▁singing , ▁the ▁first ▁two ▁vers es , ▁the ▁Gl oria ▁and ▁perhaps ▁the ▁last ▁two ▁vers es ▁are ▁often ▁s ung ▁by ▁the ▁whole ▁cho ir . ▁ ▁A ▁few ▁cho irs ▁elaborate ▁further , ▁e . g . ▁by ▁having ▁some ▁vers es ▁s ung ▁by ▁solo ists , ▁tre bles ▁only , ▁alto / ten or / b ass ▁only ▁( with ▁the ▁tre ble ▁line ▁transferred ▁into ▁one ▁of ▁the ▁other ▁parts ) ▁or ▁one ▁part ▁or ▁solo ists ▁singing ▁the ▁mel ody ▁while ▁the ▁rest ▁of ▁the ▁cho ir ▁hum s . ▁Occ asion ally ▁some ▁or ▁all ▁tre