Haas has garnered widespread praise and attention for his performances of Philip Glass' Concerto Fantasy for Two Timpanists and Orchestra, a piece conceived by Haas and completed because of his quest to spotlight the timpani.  The Concerto Fantasy features not only two timpanists, but also 14 timpani, all placed downstage in front of the orchestra.   

In 2000, Haas performed the world premiere of the piece with the American Symphony, and he has subsequently performed it at Carnegie Hall with the New York Pops, at the Ravinia Festival with the Chicago Symphony (James Conlon, conductor) and with the Seattle Symphony, St. Louis Symphony, Naples Philharmonic, Louisville Orchestra, Phoenix Symphony, New Jersey Symphony, Pasadena Symphony, Long Beach (California) Symphony, Milwaukee Symphony and Mexico City's Orquesta Filarmonica de la Ciudad de Mexico.  He performed the European premiere with the BBC Symphony in London, the French premiere with the Orchestre National de France, the Czechoslovakian premiere with the Prague Symphony Orchestra at the International Music Prague Spring Festival, the Norwegian premiere with the Bergen Philharmonic, the Australian premiere with the Sydney Symphony, the Turkish premiere with the Istanbul Philharmonic, and the Croatian premiere with the Croatian Radio Television Symphony Orchestra.  The world premiere of a chamber orchestra version was presented with the Iris Chamber Orchestra in Memphis, and the world premiere of a wind ensemble version was performed in Baltimore at the Peabody Conservatory and subsequently at the University of Arizona. 

Jonathan is featured on the newly released PHILIP GLASS Concerto Project Vol. I on Glass' Orange Mountain Music label, which includes Concerto Fantasy for Two Timpanists and Orchestra.  Conducted by Gerard Schwarz, the Royal Liverpool Philharmonic Orchestra performs the piece with Jonathan and Evelyn Glennie as timpani soloists.  The concerto was recorded in the acoustically wonderful Philharmonic Hall in Liverpool, January, 2004. 

According to an Orange Mountain Music statement, "The soloists were superb, exhibiting their well deserved recognition of being at the top of their respective fields. The orchestra, under Mr. Schwarz’s direction, performed beautifully.  Orange Mountain Music is very happy to initiate Philip Glass’ Concerto Project with this disc. The booklet included with the CD contains the arist’s bios and there comments on working with and performing Philip Glass’ music."