Henryk Mikolaj Gorecki (Polish: ['xenrik mji'kowaj gu'retski]; English pronunciation Go-RET-ski; December 6, 1933 - November 12, 2010) was a Polish composer of contemporary classical music. According to critic Alex Ross, no recent classical composer has had as much commercial success as Gorecki. Gorecki became a leading figure of the Polish avant-garde during the post-Stalin cultural thaw.

The first public performances of Gorecki's music in Katowice in February 1958 programmed works clearly displaying the influence of Szymanowski and Bartok. The Silesian State Philharmonic in Katowice held a concert devoted entirely to the 24-year-old Gorecki's music. The event led to a commission to write for the Warsaw Autumn Festival. The Epitafium ("Epitaph") he submitted marked a new phase in his development as a composer, and was described as representing "the most colourful and vibrant expression of the new Polish wave". The Festival announced the composer's arrival on the international scene, and he quickly became a favorite of the West's avant-garde musical elite. Writing in 1991, the music critic James Wierzbicki described how that at this time "Gorecki was seen as a Polish heir to the new aesthetic of post-Webernian serialism; with his taut structures, lean orchestrations and painstaking concern for the logical ordering of pitches". Gorecki wrote his First Symphony in 1959, and graduated with honours from the Academy the following year. At the 1960 Warsaw Autumn Festival, his Scontri, written for orchestra, caused a sensation among critics due to its use of sharp contrasts and harsh articulations. By 1961, Gorecki was at the forefront of the Polish avant-garde, having absorbed the modernism of Anton Webern, Iannis Xenakis and Pierre Boulez, and his Symphony No. 1 gained international acclaim at the Paris Biennial Festival of Youth. Gorecki moved to Paris to continue his studies, and while there was influenced by contemporaries including Olivier Messiaen, Roman Palester, and Karlheinz Stockhausen. He began to lecture at the Academy of Music in Katowice in 1968, where he taught score-reading, orchestration and composition. In 1972, he was promoted to assistant professor, and developed a fearsome reputation among his students for his often blunt personality. According to the Polish composer Rafal Augustyn, "When I began to study under Gorecki it felt as if someone had dumped a pail of ice-cold water over my head. He could be ruthless in his opinions. The weak fell by the wayside but those who graduated under him became, without exception, respected composers". Gorecki admits, "For quite a few years, I was a pedagogue, a teacher in the music academy, and my students would ask me many, many things, including how to write and what to write. I always answered this way: If you can live without music for 2 or 3 days, then don't write...It might be better to spend time with a girl or with a beer...If you cannot live without music, then write." Due to his commitments as a teacher and also because of bouts of ill health, he composed only intermittently during this period.

Using a quote from the above article, answer the following question: When were his first performances?
The first public performances of Gorecki's music in Katowice in February 1958 programmed works clearly displaying the influence of Szymanowski and Bartok.