Norfolk & Norwich Festival has announced the first performances of its 2025 slate. Here is a rundown of the vocal performances on offer. Mezzo-soprano Lotte Betts-Dean performs works by Scelsi, Feldman, and Schwitters, as well as pieces that “draw on medieval plainchant, experimental electronica, and techno, including works by Mathis Saunier, Stuart MacRae and new additions to the Voice Electric {…}