He was a chorister at the Augustinian 'Queen's' Monastery in Old Brno, where the choirmaster Pavel Krizkovsk took a keen interest in his musical education. After completing his basic schooling he trained as a teacher and, except for a period at the Prague Organ School, he spent 1872-9 largely as a schoolteacher and choral conductor in Brno. In 1879 he enrolled at the Leipzig Conservatory, where he developed his interest in composition under the strict and systematic supervision of Leo Grill. After a month in Vienna he retumed to Brno in May 1880; there he became engaged to one of his pupils, Zdenka Schulzová, whom he married in July 1881.
In Brno, Janacek took up his former activities, and he also founded and directed an organ school and edited a new musical journal, "Hudební listy". After composing his first opera, "Sárka", he immersed himselt in collecting and studying Moravian folk music, which bore fruit in a series of orchestral suites and dances and in a one-act opera, "The Beginning of a Romance". This was favourably received in 1894, but Janacek withdrew it after six performances and set to work on "Jenufa".
During the long period of composition of "Jenufa" (1894-1903), Janacek rethought his approach to opera and to composition in general. He largely abandoned the number opera, integrated folksong firmly into his music and formulated a theory of 'speech-melody', based on the natural rhythms and the rise and fall of the Czech language, which was to influence all his ensuing works and give them a particular colour through their jagged rhythms and lines. "Jenufa" was soon followed by other operatic ventures, but his reputation in Brno was as a composer of instrumental and choral music and as director of the Organ School. Outside Moravia he was almost unknown until the Prague premiere of "Jenufa" in 1916. The creative upsurge of a man well into his 60s is explained partly by the success of "Jenufa" in Prague and abroad, partly by his patriotic pride in the newly acquired independence of his country, and perhaps most of all by his passionate, though generally distant, attachment to Kamila Stösslová, the young wife of an antique dealer in Pisek, Bohemia.
Between 1919 and 1925 Janacek composed three of his finest operas, all on subjects with special resonances for him: "Katya Kabanova" with its neglected wife who takes a lover, "The Cunning Little Vixen" with its sympathetic portrayal of animals (and particularly the female fox), and "The Makropoulos Affair" with the 'ageless' woman who fascinates all men. Each was given first in Brno and soon after in Prague. His 70th birthday was marked by a doctorate from the Masaryk University in Brno. Early in 1926 he wrote the "Sinfonietta for orchestra", characteristic in its blocks of sound and its forceful repetitions, and later that year his most important choral work, the "Glagolitic Mass". While performance of his music carried his fame abroad, he started work on his last opera, "From the House of the Dead", which he did not live to see performed. It received its premiere in April 1930 in a version prepared by his pupils Bretislav Bakala and Osvald Chlubna.
Janacek's reputation outside Czechoslovakia and German-speaking countries was first made as an instrumental composer. He has since come to be regarded not only as a Czech composer worthy to be ranked with Smetana and Dvorak, but also as one of the most substantial and original opera composers of the 20th century.