22 Complete Warm-Up Routines. Par GROEGER BERTRAND. We can’t do without it: every good rehearsal and successful concert begins with a warm-up. For this, you need motivation, variety, methods and imagination. And that’s where this book comes in: Warm Up the Choir offers 22 complete warm-up routines, lively and compact in increasing difficulty. Whether it’s a pop choir, church choir or professional …