What are vocal scales, and why do singers practise them?
A vocal scale is a run of notes in order — most often the major scale, do-re-mi up and back down — sung on a vowel or a lip trill. Singers use scales to warm up, to move evenly across the whole range so there are no sudden jumps between registers, and to train the ear and the voice to land on exact steps. The usual pattern is to start low and move the scale up a semitone at a time, staying inside a range that feels comfortable.