When he eventually turned up back home, his family learned that he had snuck aboard the SS President Wilson, fallen asleep, and was discovered by its crew only after it had set sail for Hong Kong.
[7] After the program finished, Medalla stayed in New York and met Mark Van Doren, then a faculty member at Columbia University.
During his time in New York, Medalla became acquainted with New York-based Filipino artists, including poet José García Villa and painter Alfonso Ossorio.
[9] On returning to Manila in March 1955, Medalla transformed his family home in Ermita into an art studio and salon that he called La Cave d'Angley.
[10] During the 1960s in Paris, the French philosopher Gaston Bachelard introduced Medalla's performance of Brother of Isidora at the academy of Raymond Duncan.
During the early 1960s Medalla moved to the United Kingdom and in 1964 co-founded the Signals London gallery, which presented international kinetic art.
In 1967 he initiated the Exploding Galaxy, an international confluence of multi-media artists, significant in hippie/counterculture circles, particularly the UFO Club and Arts Lab.
Residing at the George Washington Hotel on Lexington Avenue in New York City, in 1994, he founded the Mondrian Fan Club with Adam Nankervis as vice-president.
The exhibition also featured large-scale prints of his New York 'Mondrian Events' with Adam Nankervis, and five large oil paintings on canvas created by Medalla in situ at 55 Gee Street.
He was the founder and director of the London Biennale in 1998, a “do-it-yourself” free arts festival, which hosts work by Mai Ghoussoub, Mark McGowan, Deej Fabyc, Marko Stepanov, Adam Nankervis, James Moores, Dimitri Launder, Fritz Stolberg, Salih Kayra, Marisol Cavia, and many others.
During this period he also produced the artwork Cosmic Pandora Micro-Box, published in 2018 in the book by James Cahill "Flying Too Close to the Sun: Myths in Art from Classical to Contemporary", Phaidon.
Medalla considered it a scientific and philosophical challenge, his attempt in achieving the concept of an expanding and continuously changing sculpture.
[18] The work draws inspiration from and acts as a response to the auto-destructive sculptures of Polish artist Gustav Metzger, a contributor to the Signals Newsbulletin, who called Medalla "the first master of auto-creative art."
31, was later exhibited at the 14th Biennale of Lyon, bought by Sotheby's S2 gallery, before being sold and then permanently installed for public viewing by the Philippine bank BDO at their Corporate Center in Ortigas.
[30] Early stagings of the installation were produced at exhibitions such as documenta 5, curated by Harald Szeeman, and A Survey of the Avant-Garde in Britain, both in 1972, as well as at the poorly-received POPA at MOMA at the Modern Art Oxford in 1971.
[31] In 2012, Medalla was given the Gawad Tanglaw ng Lahi award from Ateneo de Manila University, which recognizes those who have pursued Filipino identity through any channel of culture.
[32] In 2016, Medalla was shortlisted for the inaugural Hepworth Prize for Sculpture alongside Phyllida Barlow, Steven Claydon, and Helen Marten.