Having completed Gymnasium no. 4 in Kraków , Wiechowicz studied the organ at the Kraków Conservatory of the Music Society in 1908-11 as well as theory and composition at the Emil Jaques-Dalcroze Institute in Hellerau near Dresden in 1912-13 and at the St Petersburg Conservatory of the Russian Imperial Music Society in 1914-16. The studying agenda was interrupted in 1916 when he got drafted by the Russian army. After the demobilization of 1918, he settled in Kharkov, teaching solfeggio and cadence in a school managed by his wife, Walentyna Szaposznikow-Wiechowicz. He returned to Poland in 1921 and settled in Poznań, assuming the position of artistic director and conductor of the Koło Śpiewackie Polskie / Polish Singing Group, transformed into the Poznań Oratory Society in 1931. He also ran the Frederick Chopin Choir in 1927-30, Men's Choir "Echo" in 1928-30 and the Stanisław Moniuszko Mixed Choir from 1935. Meanwhile he was the editor-in-chief of "Przegląd Muzyczny", music reviewer at "Kurier Poznański" and music reporter at the quarterly "Muzyka Polska". He taught theoretical subjects at the National Music Academy and School in Poznań from 1921 and was a lecturer in music theory at the National Music Conservatory in Poznań from 1923. He resumed his music studies as a grant holder at the Schola Cantorum in Paris in 1926-7. Having earned a degree in composition from the National Music Conservatory in Warsaw in 1931, he started to lecture composition at the Poznań Conservatory.
During World War II Wiechowicz was officially employed as a lawyer in the office of the Tadeusz Halbert's forest farm in Jeleniec near Ostrów Świętokrzyski, yet he continued to give lessons in composition and theory of music as well as collecting material for textbooks in conducting, history of choral music and vocal forms. After the war he moved to Kraków and became professor of composition and theory at the National Higher School of Music until his death as well as being Dean of the Pedagogical Department and Vice-Chancellor. Among his students were Krzysztof Penderecki, Lucjan Kaszycki, Juliusz Łuciuk and Krzysztof Meyer.
Never losing touch with the singing movement, Wiechowicz was the artistic director for the Kraków area from 1947 and an honorary director of the Union of Polish Singing and Instrumental Groups from 1951. As a long-standing contributor to the publishing house Polskie Wydawnictwo Muzyczne, he wrote a number of works on the choral conducting and score reading technique, such as "Dyrygent chóralny i formy wokalne" / "Choir Conductor and Vocal Forms", "Dzieje chóru i rozwój praktyki chóralnej" / "A History of the Choir and Development of Choral Singing", "Czytanie partytur" / "Score Reading", "Podstawowe uwagi dla dyrygentów chóralnych" / "Basic Instruction for Choir Conductors".
Wiechowicz's prizes and awards include the 1st prize for Oj ty wolo for mixed choir (1928) at the 1928 Pan-Slavic Singing Meeting; State Music Award for life achievement in composing in 1939; 1st prize for Kantata żniwna (olimpijska) / Harvest cantata (Olympic) for 8-voice mixed choir (1940-47) at the National Olympic Competitions and Olympic bronze medal at the International Olympic Art Competitions in 1948; the State Arts Award of 2nd degree in 1950; 1st prize for suite Kasia for string orchestra and two clarinets (1946) at the Festival of Polish Music in 1951; Polish Composers Association's award in 1953; 1st prize for Koncert staromiejski / The Old Town Concerto for large string orchestra (1951) at the composition competition marking the World Festival of Youth and Students in Warsaw in 1954; Minister of Culture and Art Award for List do Marc Chagalla / Letter to Marc Chagall for solo voices, reciters, mixed choir and symphony orchestra (1961) in 1961.
Major compositions:
- Widmo / Phantom (We śnie mi się jawi) for voice with piano (1918)
- A że zapomnieć ciebie muszę for voice with piano (ca. 1920)
- Pocałunek / The Kiss (Slodko usta ustom rade) for voice and piano (ca. 1920)
- Czego ty bledniesz for voice and piano (1921)
- Babie lato / Indian Summer, symphonic poem for orchestra (1922)
- Na polu wiśnia for mixed choir (1922)
- Kiedy będzie słońce i pogoda for women's choir (1922)
- W olsynie, w gęstej krzewinie for mixed choir (1922)
- Kołysanka / Lullaby (Uśnijże mi, uśnij) for mixed choir (1922)
- Przedzierzgnę się siwą gołębicą for mixed choir (1922)
- Gdzie mi się podziały tulipany for mixed choir (1922)
- Z tamtej strony rzeki for mixed choir (1922)
- Moja Kasiu, moja droga for mixed choir (1923)
- Matulu moja, krakowiak for mixed choir (1923)
- Inom cię uwidzioł for men's choir (1923)
- Chodziła po sieni, lullaby for mixed choir (1923)
- Z tamtej strony jeziora for men's choir (1923)
- Nie chcę cię Kasiuniu [version I] for mixed choir (1923)
- Karafiol (Jestem sobie chłopak młody) , soldiers' song for men's choir (1923)
- W dzikim boru for mixed choir (1923)
- A siadajże na wóz [version I] for mixed choir (1923)
- Maciuś for men's choir (1923)
- Deszczyk pada for mixed choir (1923)
- Wysła na pole for mixed choir (1923)
- Pragną oczki [version I] for mixed choir (1923)
- Oj jeno ja na wojenkę pojadę for mixed choir (1923)
- Wdycki, wdycki for mixed choir (1924)
- A siadajże na wóz [version II] for string orchestra (1924)
- Matulko moja for men's choir (1924)
- Kto ma szwarną żonę for mixed choir (1924)
- Śniło mi się śniło for men's choir (1924)
- A te rudzkie dziewki for mixed choir (1924)
- Wyszła dzieweczka for men's choir (1924)
- Jenoch jednego braciszka miała for mixed choir (1924)
- Koniarze, koniarze for mixed choir (1924)
- Miałam ci ja pierwszego for men's choir (1924)
- Jestem ja dzieweczka for mixed choir (1924)
- Z tamtej strony przeory for mixed choir (1924)
- Leciały gęsi [version I] for men's choir (1924)
- Na koniczka wsiadał for mixed choir (1924)
- Służyłam u pana [version I] for mixed choir (1924)
- Ach biada mnie for men's choir (1924)
- Kiedym ja szedł for men's choir (1924)
- Ach na polu for men's choir (1924)
- Chodziłem ja po grobelce for men's choir (1924)
- Nie wiedziała co czyniła for mixed choir (1924)
- Wyleciał mi ze krza for mixed choir (1924)
- Żenie pastereczka for men's choir (1924)
- Bez wodę koniczki for mixed choir (1924)
- Jakech ja konie pasł for men's choir (1924)
- Miałam ci ja kochaneczka for mixed choir (1924)
- Pojedziemy na gon for men's choir (1924)
- Oj dziewczę, dziewczę for mixed choir (1924)
- Deszcz idzie for mixed choir (1924)
- Jak ja ciebie for mixed choir (1924)
- Stoi lipka for mixed choir (1924)
- Krakowski mosteczek for mixed choir (1924)
- Śniło się Marysi for mixed choir (1924)
- U mej matki for mixed choir (1924)
- Jak się bedę wydawała for mixed choir (1924)
- Nie chcę cię Kasiuniu [version II] for little symphony orchestra (1924)
- Służyłam u pana [version II] for mixed choir (1924)
- Kolędziołki beskidzkie for women's choir (1925)
- Kołysanka / Lullaby (Ta kolebka, ta wierzbowa) for women's choir (1925)
- Oj Janicku serdecko for voice with piano (ca. 1925)
- A wsadzę ja jabłoneczkę for voice with piano (ca. 1925)
- Córuleńku Anuleńku for voice with piano (ca. 1925)
- Osa, osa, zimna rosa for voice with piano (ca. 1925)
- Hejże Maryś rusaj sobą for voice with piano (1925)
- Czemuż ci mi moja matko for mixed choir (1926)
- Za ujazdem czarna rola for mixed choir (1926)
- Już się lasy zielenią for mixed choir (1926)
- Siedzi zajączek for mixed choir (1926)
- Wedle tego Jędrzejeczka for mixed choir (1926)
- Pod kominem, scherzino piccolo for mixed choir (1926)
- Jechało pacholę for mixed choir (1926)
- Pieśni wielkanocne w łatwym układzie / Easter songs in easy arrangement for mixed choir (1926)
- Chmiel Polski Polish wedding dance for symphony orchestra (1927)
- Kołysanka bez słów / Lullaby without Words for mixed choir (1927)
- Pastorałki / Pastorals for mixed choir and orchestra (1927)
- Słowo o Jakubie Szeli for mixed choir (1927)
- Pod borem sosna [version I] for mixed choir (1927)
- Kaczor (Uśnijże mi moje dziecię), [version I] lullaby for mixed choir (1927)
- Trzy utwory religijne w łatwym układzie / Three religious works in easy arrangement for mixed choir (1927)
- Pieśni wielkopostne w łatwym układzie / Lent songs in easy arrangement for mixed choir (1927)
- Dzień słowiański for mixed choir and wind orchestra (1928)
- Oj ty wolo for mixed choir (1928)
- Veni Creator [version I] for mixed choir (1928)
- Veni Creator [version II] for men's choir accompanied by organ (1928)
- Suita pastoralna / Pastoral suite for reciter, mixed choir and orchestra (1929)
- Kolęda w olbrzymim mieście / A Carol in a Large City, recitation for choir, solo voice and percussion (1929)
- Muzyka symfoniczna / Symphony Music for orchestra (1930)
- Rapsod / Rhapsody for orchestra and recitation (before 1932)
- Hymn na 250. rocznicę odsieczy Wiednia / Hymn for the 250th Anniversary of the Victory of Vienna for 2 voices (1933)
- Zwycięzca / The Winner for solo voice (1933)
- Kantata romantyczna / Romantic Cantata [version I] for solo soprano, mixed choir and symphony orchestra (1934)
- Mruczkowe bajki, variations II for mixed choir and 2 pianos (1934)
- Kukułecka / The Cuckoo (Kukułecka kuka, Jasio listy pise) for mixed choir (1934)
- A kto ciebie for voice and piano (1935)
- Koło mego ogródeczka for voice with piano (1935)
- Uśnijże mi moje dziecię [version II] for voice with piano (1935)
- Pod borem sosna [version II] for voice with piano (1935)
- Liście w ogrodzie for voice with piano (1935)
- Miała Kasieńka for voice with piano (1935)
- Nie chcę cię Kasiuniu [version III] for voice with piano (1935)
- Są na boru szyszki for voice with piano (1935)
- Ta kolebka (Kołysanka / Lullaby) [version II] for voice and piano (1935)
- Hej żeglajże żeglarze for voice with piano (1935)
- Hejże ino fijołeczku leśny for voice with piano (1935)
- Som w stawie rybecki [version I] for voice with piano (1935)
- Kołysanka lalek / Dolls' Lullaby (U naszego synka) for voice and piano (1935)
- Ballada / Ballade for symphony orchestra (before 1936)
- Oj siadaj, siadaj for mixed choir (1937)
- Som w stawie rybecki [version II] for 3-voice women's choir (1938)
- Powiewaj wiatreńku for women's choir (1938)
- Kwartet smyczkowy nr 1 Es-dur / String quartet No. 1 in E flat major (before 1939)
- Deszcz po szybce ścieka for mixed choir (1939)
- Na krosnach (Sam od brzega) for voice and piano (przed 1939)
- Na glinianym wazoniku [version I] for 8-voice mixed choir (1939)
- Powadziły się bieguny for voice and piano (przed 1939)
- Stuku, puku for 3-voice women's choir (1939)
- Ruta, symphonic poem for orchestra (before 1939)
- Kantata żniwna (olimpijska) / Harvest Cantata (Olympic) for 8-voice mixed choir (1940-47)
- Na glinianym wazoniku [version II] for men's choir (1941)
- Pastorałka / Pastoral (Pienia aniołów brzmią pod niebiosy; Pójdziemy bracia) for women's choir (1942)
- Dwa mazurki / Two mazurkas for violin and piano (1942)
- W Betleem sławnem for women's choir and piano or organ (1942)
- Pragną oczki [version II] for mixed choir accompanied by 2 pianos (1943)
- Kwartet smyczkowy nr 2 "Jeleniecki" / String quartet no. 2 "Jeleniecki" (1943)
- Kujawiak-ballada / ballade (Miesiączku świeć w okno moje) for 8-voice mixed choir (1944)
- Psalmodia / Psalmody for mixed choir and orchestra (1944)
- Andante d-moll / Andante in D minor for string quartet (before 1945)
- Andante D-dur / Andante in D major for string quartet and mixed choir ad libitum (before 1945)
- Od buczku do buczku for 3 women's (or children's) voices (1945)
- Krakowiak ES / Krakowiak in E flat major (Zeszły się jedna z drugą) for mixed choir (1945)
- Wlazła na wieżę for mixed choir (1945)
- Ma miła dzieweczko for women's choir (1945)
- Oj, przyszło mi, przyszło for mixed choir (1945)
- Siadaj na wóz for women's choir (1945)
- Krakowiak C (Hejże ino po skalmirsku) for men's choir (1945)
- Młodo pani na cepiecek prosi [version I] for equal voices' choir (1945)
- Młodo pani na cepiecek prosi [version II] for voice accompanied by violin (1945)
- Szumi dolina [version I] for mixed choir (1945)
- Szumi dolina [version II] for double string quartet (after 1945)
- Hosa, hosa [version I] for mixed choir (1945)
- Hosa, hosa [version II] for double string quartet (after 1945)
- Leciały gęsi [version II] for mixed choir (1945)
- Leciały gęsi [version III] for double string quartet (after 1945)
- Proso (Czyje proso ograniacie) [version I] for women's choir (1945)
- Ej za dworem na górze [version I] for equal voices' choir (1945)
- Ej za dworem na górze [version II] for voice accompanied by violin (1945)
- Zarzyjże mi mój koniczku for 3 women's or children's voices (1945)
- Trzy utwory/ Three pieces for piano (1945)
- Kasia, folk suite in 5 parts for string orchestra and 2 clarinets (1946)
- Na glinianym wazoniku [version III] for 8-voice mixed choir and 2 pianos (1946)
- Zielony gaiku for voice accompanied by violin, viola and cello (1947)
- Na glinianym wazoniku [version IV], scherzo for mixed choir and symphony orchestra (1947)
- Uważ mamo raz [version I], kujawiak for 1 or 2 women's voices accompanied by piano (1947)
- U sąsiada kalenica spadła [version I] for 4-voice men's choir and instruments (1947)
- Pochód czasów, rhythmic onomatopoeia - mass recitation for a large mixed ensemble and percussion instruments (1947)
- Trio for any string, wind or mixed instruments (1947)
- A czemużeś nie przyjechał, country scene for mixed choir and symphony orchestra (1948)
- Kołysanka d-moll / Lullaby in D minor [version I] for mixed choir (1949)
- Szła Karolinka for mixed choir (1949)
- Kaczki for mixed choir (1949)
- W gaiku for mixed choir (1949)
- Leluje for mixed choir (1949)
- Pieśń pracy / Labour Song [version I] for mixed choir (1949)
- Pieśń pracy / Labour Song [version II] for men's choir (1949)
- Tren (Wokaliza) / Lament (Vocalise) for voice and piano (1949)
- Kujawiak G (Pod borem sosna) [version III] for mixed choir and symphony orchestra (1952)
- Tam na górze jawor stoi for mixed choir (1953)
- Pado dysc for mixed choir and little orchestra group (1953)
- Pieśni Mickiewiczowskie / Mickiewicz's Songs for mixed choir (1954)
- Koncert staromiejski / The Old Town Concerto for large string orchestra (1954)
- Proso (Czyje proso ograniacie) [version II] for mixed choir (1954)
- Szyszki / Pine cones, rondo for symphony orchestra (1954)
- Kantata romantyczna / Romantic Cantata [version II] for solo soprano, mixed choir and symphony orchestra (1955)
- Jesień / Autumn (Na skrzydlach lipowych snieg) for voice with piano (1955)
- Rytmy / Rhythms for percussion group (ca. 1955)
- Rybeczki (Som w stawie rybecki) [version III] for mixed choir and orchestra (1956)
- Gołębica / The Dove, cantata for solo soprano, mixed choir and orchestra (1959-63)
- Zawołanie / The Call (Millenium) for wind and percussion instruments (ca. 1960)
- Uważ mamo raz [version II], kujawiak for women's choir, piano and percussion (1961)
- Zawitał nam dzionek for women's choir (1961)
- List do Marc Chagalla / Letter to Marc Chagall, dramatic rhapsody for solo voices, reciters, mixed choir and symphony orchestra (1961)
- Po nocnej rosie for women's choir (1961)
- Kołysanka d-moll / Lullaby in D minor [version II] for mixed choir and string orchestra (1961)
- U sąsiada kalenica spadła [version II] for women's choir, piano for 4 hands and percussion (1961)
- Przyleciał gołąbek for women's choir (1961)
Małgorzata Kosińska, Polish Music Information Center, Polish Composers' Union, October 2006