Polyphonic warm-ups work: they sharpen intonation and enhance the ability to tune in to one another. But there's a catch. As soon as singers become familiar with an exercise, the need to stay alert fades. And then routine undermines the very intention of warming up. Tijs Krammer offers a solution with his sequences. In this collection, he introduces a completely new set of warm-ups—harmonically challenging enough to remain stimulating, yet technically accessible enough for immediate use. A fresh start to every rehearsal.