The following are key locomotor skills except

The key locomotor skills refer to the movement skills that involve the coordination and control of the body. They are important for physical development and daily functioning. Among the listed options, singing is not a locomotor skill.

Crawling is the movement skill where an individual moves on their hands and knees or hands and feet while their abdomen is off the ground.

Climbing is the locomotor skill where an individual ascends or descends an object or structure using their hands and feet.

Walking is a well-known locomotor skill that involves moving forward in a rhythmic manner by alternating steps between the feet while maintaining balance.

On the other hand, singing is a form of vocalization using the voice to produce musical tones and vocal sounds, which is not directly related to body movement and coordination.

Therefore, among the given options, singing is the key locomotor skill that is not included in the list.