It varies in individuals, but many players feel nervous before the performance. Some are thinking, "I may clam the first note," or "My chops are tightening and I have to pop a high D right away." Best Brass introduces the BB Trumpet Warm-up Mute. Warm-up reduces the sound (Approximately -30dB) and allows you to warm-up in the wings, backstage, and in the moments right before the performance. Warm-up is small and light, so you can leave it in the bell while it's in the case. It also protects the bell from the damage in transit.