This is a very good question and it can be different from person to person. However, there are some general guidelines that apply to all of us that can be helpful to everyone.
Personally, I like to start memorizing music early in the day while my mind is fresh. After I get up in the morning and have a nice meal, I like to warm up and refresh the music I worked on the day before. After that, I will delve right into memorizing music.
This is not to say that this is the only time to memorize music. In fact, studies have shown that if you memorize things right before you go to sleep you will retain more information. Your mind will assimilate what you’ve memorized as you sleep!
This is not to say that either method is correct or incorrect because one size does not fit all. Some people might have their minds working best in the evening while others will be scattered and unfocused later in the day. Personally, I can work late into the night as easily as early in the day, but starting early allows me to assimilate more.
This brings us to the subject of how much you can attempt to memorize during the course of a day. You really can’t overload yourself with too much information at once. For example, if you were moving your household if you attempted to take all the boxes and furniture at once without stopping you would become completely exhausted and probably wouldn’t finish the job. However, if you were to take your time and take frequent breaks in between you would be much more capable and productive. The same thing is true for your mental work. Learning to pace yourself and work a little bit at a time is much more beneficial to you than trying to cram it all into one session. I recommend working a bit on your memorization and then taking a break by doing something completely different. Keep coming back to it throughout your practice and you will be amazed at how much more you are able to retain over time.
Thanks again for joining me Robert Estrin Robert@LivingPianos.com (949) 244-3729