Explore a 35-minute talk by Raimar Wulkenhaar on scalar quantum fields in 4-dimensional noncommutative geometry, presented at the Workshop on "Exactly Solvable Models" at the Erwin Schrödinger International Institute for Mathematics and Physics (ESI). Delve into the speaker's 25-year collaboration with Harald Grosse, focusing on renormalisable and solvable scalar QFT models in this unique geometric setting. Gain insights into key milestones and developments in this specialized field of mathematical physics, as Wulkenhaar reflects on their groundbreaking work initiated at ESI a quarter-century ago.