“You need to practice…every morning.” – Gioacchino Rossini
“…about two hours, well chosen and prudently distributed.” – Gaetano Nava
“…one hour, divided into practice-periods of fifteen minutes each, daily.” -Mathilde Marchesi
“Let the student practice anywhere from ten to twenty minutes in succession and then make a break. Sometimes, however, the singer may feel just like working for an hour or more with occasional resting spells, and, if so, there is no reason why she should not.” – Frieda Hempel
“Ten to fifteen minutes at a time.” – Amelita Galli-Curci
“Each period of work lasting no more than twenty or twenty-five minutes.” – Ernestine Schumann-Heink
“10 or 15 minutes, six to eight times a day.” – Michael Balfe