Franz Mohr has been chief concert technician for piano maker Steinway and Sons for more than a quarter century. As the close colleague of legendary musicians such as Horowitz, Rubinstein, Gould, Serkin, and many others, Franz Mohr has attended to their instruments, making delicate adjustments that affect tone, balance, and other characteristics of sound. It is Mohr who enables virtuosos to fully realize their own individual interpretative styles and...