タングルウッド音楽祭
León's composition "Horizons", written for the NDR Symphony Orchestra of Hamburg, premiered at the July 1999 Hammoniale Festival, with Peter Ruzicka conducting. In August 2000, "Horizons" had its U.S. premiere at the Tanglewood Music Festival, with Stefan Asbury conducting. León conducted the work with the Orchestre Symphonique de Nancy (France) in March 2002.