Here's what I have done. It's not the best way to do it, but it was the easiest at the time for me, and I have had no reason to change it:
1. I created a folder (not a query) called Year.
2. I created seven subqueries here named Unknown year, Pre-1960's, 1960's, 1970's, 1980's, 1990's and 2000's. These had format $cut(%date%,4)|%artist%|$if2(%album%,<Unknown album>)|[$num(%tracknumber%,2) - ]%title%
and criteria (this is the important part) date GREATER 1969 AND NOT date GREATER 1979
for 1970's, date GREATER 1979 AND NOT date GREATER 1989
for 1980's and so on. Unknown year had date MISSING
and Pre-1960's had NOT date MISSING AND NOT date GREATER 1959
That way, all the subfolders of these queries will be a single year (e.g. 2000, 2001, 2002 and so on for the 2000's query), and then the standard artist/album thingy. You might want to change some things to include months, if that is what you're after.