During his seminary years, the confidence of his peers and superiors led to his election as student prefect. Muzychka's musical training also bore much fruit. In 1949 he began directing the seminarians choir for the Ukrainian Liturgies broadcast on Vatican Radio and, after his ordination, contributed many recorded sermons for VR broadcasts. He was the first to transcribe Izydor Dolnytsky's Hlasopisnets (church melodies) from the old 4-line staff and tetrachord scale into modern musical notation in the keys of F and B flat. The book was printed in manuscript form for internal use in 1951 and published under the name of Napivnyk in 1959.
Father Ivan was present at the secret consecration of three bishops by Cardinal Slipyi on 2 April 1977: Lubomyr Husar, Ivan Choma, and Stefan Czmil. Having refused the accept the episcopate himself, he nevertheless agreed to act as the sole witness and also to cantor at the Divine Liturgy of episcopal chirotonia. Two of the three bishops were later recognised by Saint John Paul II, in 1996: Husar succeeded Slipyi as Major-Archbishop in 2001, Choma became UGCC procurator to the Holy See, and Czmil is famous for having being spiritual advisor and teacher to Jorge Maria Bergoglio (the future Pope Francis) in Argentina. Czmil died in 1978, before the papal recognition could occur.
In 2013, he received a doctorate honoris causa from the Ukrainian Catholic University in Lviv.
Father Ivan died an hour before the arrival of Patriarch Sviatoslav and the hierarchs of his permanent Synod. Together with Metropolitan Volodymyr Viityshyn and Bishop Venedykt Alekseychuk, the patriarch prayed panakhyda over the mortal remains of Father Ivan. Prayers were offered for his eternal repose across the globe, from Kyiv to Sydney, Australia. Ivan Muzyczka's passing to eternity marks the passing away of an entire epoch in the history of our Church.
The first priestly parastas was celebrated on Tuesday evening, 23 February, by Kyr Hlib Lonchyna, Eparch of the United Kingdom of Great Britain, assisted by Kyr Dionisio Lachovicz, Apostolic Visitor for Ukrainians in Italy, and Kyr Venedykt Alekseychuk, auxiliary of Lviv, with many priests concelebrating including Father Genesio Viomar, Basilian Protoarchimandrite and Archpriest Bohdan Prakh, Rector of the Ukrainian Catholic University in Lviv.
A letter was read, addressed to Patriarch Svaitoslav from Cardinal Sandri, Prefect of the Congregation for the Eastern Churches, expressing condolences to the Ukrainian Greek-Catholic Church from the Apostolic See, and offering praise and thanksgiving for Father Muzyczka's long and dedicated mission. And his homeland also paid its respects in the person of the Ambassador of Ukraine to the Holy See.
Ivan Muzyczka was interned in the sobor's crypt, next to his co-workers, Bishops Ivan Choma, and Stefan Czmil, and also near Archbishop Yosyf Sembratovych, who died in Roman exile in 1900.