Peder Karlsson is a Swedish singer, arranger, conductor and educator whose influence on contemporary a cappella music spans four decades. A founding member of the legendary Real Group — with whom he recorded 16 albums and won two Grammy Awards — he has helped shape the sound of vocal ensemble music worldwide. Beyond performance, Peder is widely respected as a teacher and workshop leader, empowering vocal groups to become self-sufficient, deeply listening ensembles. He is also the creator of Choirs for Ecocide Law, an international choral concert project raising awareness of large-scale environmental destruction as an international crime.
Rosana Eckert (America) is an internationally acclaimed jazz vocalist, improviser, songwriter, arranger, and educator known for blending virtuosity with warmth and originality. Deeply rooted in jazz yet stylistically adventurous, she has performed and recorded with artists such as Bobby McFerrin, Christian McBride, and New York Voices, and appeared on the Grammy Award winning composition “Eberhard” by Lyle Mays.
A dynamic bandleader and recording artist, she brings expressive storytelling and inventive improvisation to every stage. Rosana is Principal Lecturer of Jazz Voice at the University of North Texas, where she has helped shape one of the world’s leading vocal jazz programs while inspiring singers across generations.
Julian Knörzer (Germany) studied school music and choral conducting (MH-Freiburg, RAMA Vocal Center). He is active in the German vocal scene as a choir director, beatboxer, singer, and arranger (Jazzchor Freiburg, Twäng!, UNDUZO, Acoustic Instinct) and works internationally as a lecturer. In the field of beatboxing, he specializes in accompanying vocal ensembles, which led him to publish the book “Beatbox Your Choir – Chöre und Vocal Groups perfekt begleiten” (Schott) in 2015. Julian Knörzer teaches jazz/pop choir conducting and beatboxing at the Freiburg University of Music and the Tübingen University of Church Music. In addition to his teaching activities and active concert life, he co-founded the Black Forest Voices vocal music festival in 2019.
Stefan Rheidt is a German vocal coach, choir director, and arranger whose work bridges jazz-informed musicianship and contemporary vocal pedagogy. He trained at the Swiss Jazz School in Bern and the Complete Vocal Institute in Copenhagen — a dual background that shapes his practice-driven approach to both individual and ensemble singing. Stefan is the founder of Vocalive, a vocal academy offering coaching and workshops for singers and groups, and directs the Jazzchor Vocalise, where he brings together ensemble precision and stylistic authenticity. Beyond the choir room, he performs with the ukulele trio Ukulala, adding a playful, stage-ready dimension to his musical life.
Maggie Horrer is a German jazz vocalist and educator whose work spans performance, teacher training and children's vocal music. She studied jazz vocals in Freiburg and Lucerne, graduating in 2017 with a Master of Arts in Jazz Vocals and Music Education. Teaching voice since 2006, she currently trains aspiring music educators at the Merian-Schule in Freiburg and leads workshops for the Singen mit Kindern Foundation, dedicated to vocal music for children. As a performer, she sings with the Jazzchor Freiburg, and her warm voice is perhaps most widely known through her recordings for the beloved Lauschelieder children's album series.
Nina Ruckhaber is a German vocal producer, festival organiser and singer whose work connects performers, audiences and communities across the a cappella world. Co-founder and organisational director of the Black Forest Voices festival, she has spent over fifteen years singing with the Freiburg Jazz Choir while building an extensive network across the popular choir and a cappella scene — collaborating with artists and ensembles including MAYBEBOP, ONAIR and New York Voices. As media director of the German Youth Choral Association, she shapes how choral culture is communicated nationally, and through her own platform Ninas VoxBox she has created a dedicated online home for vocal music.
Ingo Rau is a German sound engineer, producer and pioneer in immersive live concert sound. He studied Psychology at the University of Freiburg and Tonmeister in Detmold before founding AMPS Factory Studios in Freiburg, specialising in audiophile analogue recording. His approach to spatial sound was shaped early by mentorship at the Experimentalstudio des Südwestfunks, where the groundbreaking Halaphon system — used in works by Karlheinz Stockhausen — first opened his ears to the possibilities of sound in motion. Since 2002, he has developed and toured internationally with immersive surround sound concepts for live concerts, bringing extraordinary sonic depth to stages across Europe, Asia and Australia.
Bam Rodríguez is a Venezuelan-born GRAMMY® Award-winning bassist, composer, educator and social activist whose artistry spans classical music, modern jazz, world music and Latin traditions. Trained in the renowned El Sistema programme alongside Gustavo Dudamel, he went on to earn dual master's degrees from the Royal Conservatory of Brussels and the Conservatorium van Amsterdam. As a member of Arturo O'Farrill's Afro Latin Jazz Orchestra, he won the 2022 GRAMMY® for Best Latin Jazz Album, and has performed at Carnegie Hall, the North Sea Jazz Festival and Taipei's National Theater with artists including Chucho Valdés, Paquito de Rivera and Roy Hargrove. He is also the founder of We Are Starting a School, connecting underprivileged students worldwide with New York-based music educators.
Gabriel Hahn is a French-German drummer, percussionist, vocalist, composer and educator whose work spans jazz, contemporary vocal music, body percussion and cross-cultural collaboration across four continents. Raised in Munich within a family of classical musicians, he holds a master's degree in composition and arrangement from the Music College of Dresden and has toured internationally for over a decade as drummer and body percussionist with vocal jazz legends The New York Voices. He has recorded with the Brussels Vocal Project, performed with Ensemble Atonor at the Donaueschingen Musiktage, and collaborated with award-winning Taiwanese a cappella groups Voco Novo and O-Kai Singers. His 2025 solo debut album Missing Pieces to Multipolar Imperturbability reflects his multilingual, boundary-crossing artistic vision. Now based in Taipei, he serves as Co-Artistic Director of the Vocal Asia Festival and runs Glocal Culture Exchange (家柏文化交流), connecting Taiwan's vibrant music scene with the global jazz community.
Christine Liu is a Taiwanese composer, arranger, vocalist, organist and one of Asia's most influential figures in contemporary a cappella music. Deeply inspired by Indigenous Taiwanese culture as much as by Western composition and liturgical tradition, her work as a musician and curator consistently pushes at the boundaries of what vocal music can hold. She leads Voco Novo — whose album Goza Goza won the Golden Melody Award — as alto and Artistic Director, and serves as Artistic Director of the Vocal Asia Festival, one of the continent's most important platforms for vocal music. A prize-winning arranger whose works are performed across Asia, Europe and the Americas, she is also principal organist of Holy Family Catholic Church in Taipei and founder and conductor of Coro Novo, one of Taiwan's first pop choirs.