Billy Kristanto graduated from Hochschule der Künste in Berlin, Germany, where he majored in harpsichord under Mitzi Meyerson. He furthered his studies in harpsichord and fortepiano under Ton Koopman and Stanley Hoogland, and received his postgraduate certificate from The Royal Conservatory in The Hague, Netherlands. In 2009, he successfully defended his doctoral thesis titled “Musical Settings of Psalm 51 in Germany ca. 1600-1750 in the Perspective of Reformational Music Aesthetics” under the guidance of early music specialist Prof. Dr. Silke Leopold at the University of Heidelberg, Germany. His second doctoral degree in systematic theology was conferred in 2011 following the completion of his dissertation on "The Glory of God in the Thought of John Calvin".

Particularly interested in historically-informed practice, Billy has given musical direction to several oratorio societies and performances in major cities in Indonesia, Singapore, Hamburg, and Berlin. He also lectures at The International Reformed Evangelical Seminary.

Billy also writes articles on music for international journal, presents papers on music at international conferences. Among his writings are “Reformation and Music” (Unio cum Christo 3 [2017]), “Pop Music, Pragmatism, and Christianity” (Ethos Institute, 2017), The Place of Music in the Church and in Society (Singapore: Sower Publishers, 2018), “Calvin dan Potensi Pemikirannya bagi Ibadah Kristen” (Veritas 19/2 [2020]), “Exil und religiose Identität in einigen Kantaten von Johann Sebastian Bach” (European Journal of Theology 29/2 [2020)”, “The Beauty of Music” (Ethos Institute, 2022), “Ars Moriendi, The Art of Dying” (Ethos Institute, 2022), “J. S. Bachs Sterbekantaten im Lichte der lutherisch-orthodoxen und spätmittelalterlichen ars moriendi” (Evangelische Theologie 83/6 [2023]), and “Mirror, mirror on the wall, who’s the most beautiful of them all?” (Ethos Institute, 2024).

As an ordained pastor at Gereja Reformed Injili Indonesia, Billy currently serves the International Reformed Evangelical Church in Berlin, Hamburg, Munich, Switzerland, and Stockholm (irec-europe.org).

The Indonesian/Australian pianist Calvin Abdiel was born in 2001 in Indonesia. He showed interest in classical music from the age of five. Moving to Australia in 2011, he continued his music studies at the Sydney Conservatorium High School and later at the Sydney Conservatorium. He completed his Bachelor of Music (Performance) degree with First Class Honours at the Sydney Conservatorium of Music under Natalia Ricci who remained his piano teacher and mentor throughout his formative years. Calvin is currently undertaking his Master of Arts degree with Prof. Eldar Nebolsin at the Hochschule für Musik Hanns Eisler with the assistance of a DAAD Postgraduate Music Scholarship and a SCM George and Margaret Henderson Overseas Postgraduate Scholarship.

Calvin has had masterclasses with guest artists such as Orli Shaham, Justas Dvarionas, Michael Endres and Vyacheslav Gryaznov at the Sydney Conservatorium as well as Angela Hewitt in a Musica Viva sponsored masterclass. He’s a scholarship holder of the Music Academy of Liechtenstein and takes part in the intensive weeks and activities held by the academy.

Calvin received several prizes at national and international competitions. Among others, he won the “George Frederick Boyle Third Prize” and the “Nancy Weir Best Australian Pianist Prize” in the prestigious “Sydney International Piano Competition” (the Sydney) as its youngest competitor in 2021. He also received the “Australian Elizabethan Theatre Trust Prize” of an overseas scholarship to further his musical career. Following the competition, he embarked on a debut recital tour of Australia, presented by the Sydney. Calvin won the 2nd prize at the “International Competition for Young Pianists ’Steps to Mastery’” in St Petersburg in 2017, the 2nd prize and a string of awards (Concerto Prize, Queensland Symphony Orchestra Vote Prize and Audience Prize) at the “Lev Vlassenko Piano Competition” as its youngest participant in Australia in 2017, the 3rd prize in the “Val de Travers International Piano Competition” in Switzerland in 2018 and the 1stprize in the “Ananda Sukarlan Award International Piano Competition” in Jakarta in 2020. As the winner of the 2021 “SCM Piano Concerto Competition”, Calvin performed Prokofiev’s Piano Concerto No. 3 in May 2022 with the Sydney Conservatorium Symphony Orchestra. In the same year, he was the recipient of the “Frank Albert Prize for Music” at the Sydney Conservatorium.

Calvin made his orchestral debut in 2017 with the St Petersburg State Capella Symphony Orchestra and gave subsequent performances with the Queensland Symphony Orchestra and the Swiss orchestra Les Chambrites. He has worked with conductors including Anatoliy Rybalko, Gerard Schwartz, Richard Davis, Roger Benedict and Paul Terracini. In 2022, he performed Prokofiev’s Piano Concerto No. 4 as the soloist in the inaugural concert of the G20 Orchestra at the Candi Borobudur (UNESCO World Heritage Site), which was broadcasted on the national television in Indonesia (TVRI) and streamed globally online.

Calvin has given high profile performances in numerous countries, including Australia, Austria, Russia, Indonesia, Germany, Denmark, and Switzerland. He’s an avid chamber musician and has performed in the Canberra International Music Festival in 2021 and the Out West Piano Festival in 2023. He was the founding member and former conductor of the youth orchestra Cantate Deo Chamber Orchestra from 2020 to 2023.

His live performances in Australia have been recorded by ABC Classic FM and Fine Music FM.

Calvin’s musical activities throughout his education have been supported by the SCM Henderson Scholarships, Sydney Eisteddfod Kawai Piano Scholarship, Theme and Variation Foundation, Institut Francais d’Indonesie (IFI), Australian Elizabethan Theatre Trust, and the International Piano Foundation “Theo Lieven”. He was invited as scholarship holder to attend the Lieven Piano Summer School in 2022 and 2023, where he worked with the pianists Andreas Steier, Lilya Zilberstein, Paul Roberts, Davide Cabassi, Arie Vardi, Alexei Volodin, Alon Goldstein, and Robert Mcdonald. In 2023, a scholarship from IFI enabled him to study the piano works of Ravel with Pascal Roge in Nice, France.

The IREC Europe Choir was founded alongside the church in 1999 as part of the church's ministry to praise God and share His blessings through worship. The works performed contain both textual and musical content to bring people closer to God. The choir performs a diverse range of church music; from Baroque composers such as Heinrich Schütz, J.S. Bach and G.F. Händel, to the Romantic period with Mendelssohn, and to classical modernism with Paul Hindemith.

Rev. Dr phil., Dr theol. Bily Kristanto, leads the rehearsals together with a musician trained from the choir. The choir rehearsals take place both once a week together on the Sunday before the service in the church and individually for each voice using digital media at home. Around 10 to 20 singers sing in the choir, who are both church members and active parishioners.

The choir usually sings during services, accompanied by piano or organ, at Sunday services, Christmas services and other festive services such as Good Friday, Easter and Whitsun.

In July 2010, the IREC Berlin church choir, together with the choir of the Reformed Oratorio Society Singapore, organised a "Music Evening &Angklung Ensemble in Praise of God", presenting works by J.S. Bach, Mendelssohn, J. Brahms, J.H. Schein, H. Schütz, A. Hammerschmidt and Mozart.

In 2012, the choir also sang in a revival service with "Vater unser im Himmelreich", J.S. Bach BWV 416 and "Ich bin die Auferstehung", H. Schütz SWV 324.

Over the years, the IREC Europe Choir has achieved a great deal. The choir has always actively participated in our annual church camps and has also been involved in pastoral work in prisons and retirement homes.

In 2023, the IREC Europe Choir had the opportunity to perform Schubert's Psalm 23 during Stephen Tong's Gospel Rally, sharing the message of God's Word through the power of music.