To assess whether the resulting keyboard was good enough for typing, the computer scientists first conducted a study with a piano professor. He was asked to "play sentences" that were translated into music pieces shown on a sheet. "Without prior practice he was able to enter text with a top speed of over 80 words per minute. This corresponds to the performance rate of a professional typist using the QWERTY keyboard", said Antti Oulasvirta, Senior Researcher at Max Planck Institute of Informatics.
Moreover, the researchers trained a hobby pianist to generate text by learning the assignment of words and letters to notes. After six months of training, she was also able to enter sentences at up to 80 words per minute – similar to the professional pianist but without reading from a music sheet. Now she can write e-mails and posts on Facebook faster than with the conventional keyboard, and at the same time she trains her piano playing skills.
With their study the researchers examined the question of why pianists can play play notes on a piano twice as fast as professional secretaries can type letters on a keyboard. Therefore they investigated which factors of piano playing might improve text typing, in particular as it is done on input devices such as a so-called QWERTY keyboard.Play it again, Stan (and Steve).
Update: via e-mail Stan Liebowitz informs us that in the early days of typewriters some manufacturers did try keyboards modeled on the piano. The thinking being that some would already be familiar with the finger motions needed. Alas, for them, the public wasn't locked-in to the piano!