His play Six Dance Lessons in Six Weeks opened on Broadway at the Belasco Theater starring Polly Bergen and Mark Hamill. The play premiered in Los Angeles where it set records at the Geffen Playhouse in a production starring the legendary Uta Hagen in her last role. It has since been translated into 14 languages and opened in over 24 countries with productions in cities including Berlin, Sydney, Melbourne, Vienna, Madrid, Tokyo, Tel Aviv, Jerusalem, Amsterdam, Budapest, Helsinki, Prague, Istanbul, Hamburg, Munich, Athens, Seoul, Johannesburg, and London. In Australia, it was performed in 2006 by Todd McKenney and Nancye Hayes and became the most successful play in the Ensemble Theatre's 58-year history. Other international stars who have played the leading role of Lily include Leslie Caron, Constance Towers, Claire Bloom, Loretta Swit, Elke Sommer, Lola Herrera, Miriam Zohar, Mitsuko Kusabue, and The Kessler Twins. Alfieri adapted Six Dance Lessons in Six Weeks into a feature film starring Gena Rowlands, which was released in 2014.
