John D. Witvliet is director of the Calvin Institute of Christian Worship and professor of worship, theology, & congregational and ministry studies at Calvin College and Calvin Theological Seminary. His responsibilities include oversight of the Institute's practical and scholarly programs, and teaching courses at both the college and seminary. His areas of interest include the history of Christian worship, worship practices in various denominations, biblical and systematic theology of worship, the role of music and the arts in worship, choral music and consulting with churches on worship renewal. María Eugenia Cornou is Program Manager for International and Intercultural Learning for the Calvin Institute of Christian Worship. Her areas of responsibility include international programs, curating web and print resources including translations of worship resources into multiple languages, facilitating conversations and networking with scholars, teachers of worship, and other church leaders, and grantmaking support. She is from Buenos Aires, Argentina, where she taught biblical studies and was administrative director at International Baptist Theological Seminary. Maria holds degrees in public accounting and theology and is finishing a PhD in theology from the Free University of Amsterdam on the topic of Protestant worship in Argentina. Joel Schoon-Tanis has written and illustrated several books (recently 40: the Biblical story), painted murals around the world (including Kenya, Zambia, the Separation Wall in Palestine), and painted nearly a gazillion paintings in his career. In 2016 one of these was presented to the Pope.