sun - filled ▁hills ▁of ▁T usc any " ▁( and ▁shown ▁in ▁the ▁exhibition ▁poster ) ▁which ▁Jones ▁writes ▁could ▁readily ▁be ▁taken ▁for ▁a ▁post - im pression ist ▁original . ▁In ▁his ▁view , ▁R iley ▁shares ▁Se ur at ' s ▁" jo y ▁for ▁life ", ▁a ▁simple ▁but ▁radical ▁delight ▁in ▁colour ▁and ▁seeing . ▁ ▁Work ▁ ▁It ▁was ▁during ▁this ▁period ▁that ▁R iley ▁began ▁to ▁paint ▁the ▁black ▁and ▁white ▁works ▁for ▁which ▁she ▁first ▁became ▁known . ▁They ▁present ▁a ▁great ▁variety ▁of ▁geometric ▁forms ▁that ▁produce ▁sens ations ▁of ▁movement ▁or ▁colour . ▁In ▁the ▁early ▁ 1 9 6 0 s , ▁her ▁works ▁were ▁said ▁to ▁indu ce ▁sens ation ▁in ▁view ers ▁as ▁varied ▁as ▁se as ick ▁and ▁sky ▁div ing . ▁From ▁ 1 9 6 1 ▁to ▁ 1 9 6 4 , ▁she ▁worked ▁with ▁the ▁contrast ▁of ▁black ▁and ▁white , ▁occasionally ▁introdu cing ▁t onal ▁scales ▁of ▁grey . ▁Works ▁in ▁this ▁style ▁compr ised ▁her ▁first ▁ 1 9 6 2 ▁solo ▁show ▁at ▁Mus gra ve ' s ▁Gallery ▁One , ▁as ▁well ▁as ▁numerous ▁subsequent ▁shows . ▁For ▁example , ▁in ▁Fall , ▁a ▁single ▁per pend icular s ▁curve ▁is ▁repeated ▁to ▁create ▁a ▁field ▁of ▁varying ▁optical ▁frequencies . ▁Vis ually , ▁these ▁works ▁relate ▁to ▁many ▁concerns ▁of ▁the ▁period : ▁a ▁perce ived ▁need ▁for ▁audience ▁participation ▁( this ▁rel ates ▁them ▁to ▁the ▁H appen