The Jungarian bass and music pedagogue, János Klézli, studied at Kandó Kálmán Villamosipari Műszaki Főiskola (Kandó Electric Industry Technical College). He began his musical studies in his hometown Szekszárd (violin, piano and singinh). After completing his studies he was admitted to the Conservatory Liszt Ferenc Zeneművészeti Egyetem (Ferenc Liszt Academy of Music): vocal faculty. His teachers there were József Simándi and Zsolt Bende. He graduated with honors in 1988. In May 2003, he received his DLA (Doctor of Liberal Arts) degree in Music Performing Arts from the Ferenc Liszt Academy of Music. Thesis title: Johann Sebastian Bach egyházi kantátáinak basszusszólói (J.S. Bach's church cantatas bass solos)..
János Klézli regularly gives concerts of the Baroque, classical, romantic and contemporary composers. He has performed many operas and oratorio by Purcell, Bach, Haydn, Buxtehude, Handel, Mozart, Schubert, Vivaldi, Liszt, Kodaly and Arvo Pärt.
Since September 1988, János Klézli teaches at the Ferenc Liszt Academy of Music in Budapest, and since 1992, at the Kodály Zoltán Zenepedagógiai Intézet Kecskemet (Zoltán Kodály Pedagogical Institute of Music in Kecskemet): Conducting and Choral Conducting Department. From 2008: he is also University Professor at Beijing Central Conservatory of Music, He regularly gives master-classes in Hungary and abroad, including the Nemzetközi Kodály Szemináriumokon (Kecskemét Kodály International Seminars), and South Korea (Seoul), China, Great Britain, the British Kodály Academy.
Recordings: Zoltán Kodály: Magyar Népzene (Hungarian Folk sons) (CD, 2005); Z. Kodály: orgonás művei (organ works) (CD, 2008).
Johann Sebastian Bach egyházi kantátáinak basszus szólói (J.S. Bach's church cantatas bass solos) (Magyar Bach Társaság kiadványa, 2006).
Awards and Honors: A Kodály Intézetért (The Kodály Institute, 2004).