Bel canto
Early 19th-century teachers described the voice as being made up of three registers. The chest register was the lowest of the three and the head register the highest, with the passaggio in between. These registers needed to be smoothly blended and fully equalized before a trainee singer could acquire total command of his or her natural instrument, and the surest way to achieve this outcome was for the trainee to practise vocal exercises assiduously. Bel canto–era teachers were great believers in the benefits of vocalise and solfeggio. They strove to strengthen the respiratory muscles of their pupils and equip them with such time-honoured vocal attributes as "purity of tone, perfection of legato, phrasing informed by eloquent portamento, and exquisitely turned ornaments", as noted in the introduction to Volume 2 of Scott's "The Record of Singing".