Müller was a self-thaught artist. He worked on the building, at post office, at the Television at the opera andin a printing office before he finally became a freelance artist in 1971. He participated in countless group and solo exhibitions and lived and worked in Zurich.

After school he stayed in a farm in the canton of Vaud, learned the profession of Spengler and was casual worker. In 1960 he started intense painting. Numerous works of him are in public and private collections. Fritz Müller felt that all people should be able to afford his art and sold his work for low prices being affordable for all. If he found a work especially succeeded, he reproduced it in a manufactory-like manner. For this, he was supported by people hired for this process, however, the final touches and the applying of the varnish was allways done by Müller himself. Samples found in the Internet.