Legaspi spent many years as magazine illustrator and artistic director in advertising agencies, while he took time in between his work to do paintings. In 1968 Legaspi finally left advertising to devote his time to painting. His subsequent works significantly modified the cubist expression in the Philippines with rhythmic curvilinear lines and planes.
Legaspi explored representation in a cubist context, adapting Western style to local Filipino sensibility and temperament. For Legaspi, the emotive aspects of his paintings eventually gave way to more immediate concerns with the synthetic elements of line, space, colour and texture. Legaspi adopted the use of geometric fragmentation of forms, weaving social commentary and putting together the mythical and modern into his overlapping and interacting shapes. While his work shows the influence of cubism, his figures overlap and cut through space in transparent curvilinear rhythms, achieving a richly textured combination of hues and tones. Except for his earlier monochromatic canvases, Legaspi's paintings fully realize the expressive potential of colour, with a variety of subjects from dancers and rock gardens, to dynamic street scenes.