9 2 0 ▁– ▁ 1 3 ▁March ▁ 1 9 9 6 ) ▁was ▁a ▁Belg ian ▁pian ist ▁and ▁teacher . ▁ ▁Life ▁ ▁Mer cen ier ▁was ▁known ▁as ▁an ▁influ ential ▁ped agog ue ▁in ▁Br uss els , ▁then ▁in ▁Li ège . ▁She ▁was ▁a ▁fer vent ▁advoc ate ▁of ▁contemporary ▁music , ▁but ▁also ▁performed ▁Ch op in ▁under ▁the ▁b aton ▁of ▁Charles ▁M unch ▁and ▁P ou len c ▁with ▁the ▁composer ▁. ▁ ▁She ▁was ▁a ▁member ▁of ▁the ▁group ▁" S ém inaire ▁des ▁Arts " ▁created ▁in ▁August ▁ 1 9 4 4 ▁in ▁Br uss els . ▁In ▁the ▁concert ▁series ▁of ▁this ▁group , ▁on ▁ 2 8 ▁February ▁ 1 9 4 7 ▁she ▁premier ed , ▁together ▁with ▁the ▁fla ut ist ▁Her lin ▁Van ▁Bot er da el , ▁the ▁Son at ina ▁for ▁fl ute ▁and ▁piano ▁by ▁Pierre ▁Bou lez , ▁a ▁work ▁that ▁had ▁been ▁composed ▁a ▁year ▁earlier ▁for ▁Jean - Pierre ▁R amp al , ▁but ▁had ▁not ▁been ▁performed ▁by ▁him ▁. ▁The ▁Son at ine ▁was ▁the ▁second ▁work ▁in ▁which ▁Bou lez ▁used ▁serial ▁technique , ▁after ▁the ▁Not ations ▁for ▁piano ▁of ▁ 1 9 4 5 ▁. ▁She ▁also ▁gave ▁the ▁first ▁Belg ian ▁performance ▁of ▁the ▁final ▁version ▁of ▁Bou lez ' s ▁Third ▁P iano ▁Son ata ▁and ▁premier ed ▁works ▁by ▁Karl hein z ▁Stock hausen ▁( K lav ier st ücke ▁I