So not only did sleep lead to a higher level of performance after the same amount of practice, but when participants returned to the same material, it helped them reach the desired level of performance in half the time?
This would imply a huge time and effort savings. Because if we can hop into the practice room in the morning, and work a piece back up to a higher level than it was the day before in half the time it would normally take, we could use that extra time and energy to do so much more detail work, or spend time on other repertoire.
And with regards to memory, it gets even better.
Been trying off and on to learn guitar (and a couple other things) for the last couple of years. Gonna give this a try and see if it helps any.