Hans von Bülow? Niccolò Paganini? Jennie Fowler Willing? Maria Malibran? Charles Haddon Spurgeon? Anton Rubinstein? August Wilhelmj? Ole Bull? Ignacy Paderewski? Franz Liszt? Jascha Heifetz? Fritz Kreisler? Question for Quote Investigator: There is a popular saying about the enormous importance of regularly engaging in practice to maintain prowess as a performer in music and other …