He was the oldest of four siblings and he spent his youth bottling wine with his father who was a wine and grains merchant. He wanted to become a teacher but this idea didn't last long. At the age of sixteen he discovered he had a love of clothing by frequenting the home of Luigi Bigi, a tailor who lived in the same town and who reproduced French fashion in Milan in the 1930s. In 1952, Giorgio Sarassi who, with Bigi's help, had made his fortune in the business of fabrics for high fashion, found Tirelli a job in Milan: a delivery boy and display designer for Marco, a fabric shop in the Via Montenapoleone. Almost directly across the street was the boutique of Mirsa where Beppe Modenese worked with Paola Carola. In order to save money, in order "to survive because our pay was minimal," Tirelli recalled in his autobiography, Vestire i sogni (written with Guido Vergani for the Feltrinelli publishing house), Tirelli and Modenese decided to rent a place together.
In 1955, at the age of 27 he met Pia Rame and Carlo Mezzadri who had just purchased the theatrical costume maker Finzi. They offered him a chance to try out. There he met Mila de Nobili who was making the costumes for Maria Callas in La Traviata de Luchino Visconti staged at La Scala in 1955. Therefore, he met Luchino Visconti and also Piero Tosi, who was also a costume designer and worked several times with Visconti, specially in the films Il Gattopardo and Death in Venice for which he was nominated to the Academy Awards. He was able to participate in La Traviata by making the costumes for the feminine chorus. Before his death he worked on the costumes of another version of La traviata, this time by Muti, with Gabriella Pescucci.
Then he moved to Rome to work in the Sartoria Safas for the sisters Emma and Gita Maggioni until 1964 when he set up in business for himself. He learned about the costume filology thanks to Gino Censani.
He was a costume collector, defining himself as "A fashion archeologist". He used to say that he did "the archeological expeditions" every time he bought a costume. Concetta Garzoni used to sell him costumes from the Noble class and that were almost new, only used once for a ball or other special occasion.
Tirelli's costume collection was used for cinema and theater. He had a passion for authenticity and collectionism that reflects in the film Morte a Venezia (1971) from Luchino Visconti where he dressed up Silvana Mangano; Most of the costumes in the film were authentic. The objective of using authentic costumes was to make the movements of the actors heavier and make them look more realistic. The sketches for the costumes of Morte a Venezia were done by Piero Tosi.
He worked with the biggest names of theater costumes in the second half of the twentieth century, from De Nobili, Piero Tosi, Pierluigi Pizzi, Luciano Damiani, and Danilo Donati to Gabriella Pescucci, Vera Marzot, Gitt Magrini, Ezio Frigerio, Milena Canonero, Marcel Escoffier, Maurizio Millenotti and Maurizio Monteverde. His contribution was essential to them in terms of culture, philology of fashion, the recovery of age-old techniques, the quest for authentic outfits (he had a Collection of 15,000 items, dating from the seventeenth century to the days of Chanel and Dior) in almost archaeological excavations in attics, lofts, abandoned armoires, among the rags of the flea markets.
But in 1968 came the "Anti-fashion movement", the boom of the street-style. The art falls into decay and Tirelli himself says: "Magari c'è intelligenza, ma la vera moda, la ricerca, l'invenzione è cosa del passato". ("Perhaps there is intelligence, but the true fashion, the research, the creativity belong to the past").
In 1986, Tirelli donated 100 authentic outfits and 100 theatrical costumes to the Galleria del Costume of Palazzo Pitti in Florence. Since his death, his sartoria has been run by Dino Trappetti, Gabriella Pescucci and Giorgio D'Alberti.
- Manuale di comunicazione, sociologia e cultura della moda. Volume V, Performance. Antonella Giannone e Patrizia Calefato, Roma. Meltemi, 2007.
- Storia del costume teatrale, P. Bignami. Roma, Carocci, 2005.
- Erasmus student in Italy in third year of licence in Arte dello Spettacolo, (Spectacle Arts) subject : [Storia del costume nello spettacolo] by Sofia Gnoli. (2008-2009).