The leporello style of binding was popular in Europe for many many years, and only recently became popular in North America. I learned this binding in a workshop with Barb Tetenbaum at Sitka Center in Oregon.
The name leporello is derived from the opera Don Giovanni. Leporello was his manservant. He kept a record of Don Giovanni's female conquests in a book. At the end of Act II he spread the book across the stage. It's an accordion fold of unlimited width. Pages are joined to form the accordion.