[DoctorOhh]

Originally Posted by DrMartinus

I click on the title column header and then on the author column headers, but it either sorts by title or by author, and does no sub-sort like to sort all the titles of one author alphabetically. What else is there to do to make that sub-sort work?

You are doing it correctly. Sorting by Title then by Author will have all the titles for any author in "Library Order". Which means that a book like "The Client" will be sorted as if it was "Client, The", You can change this if you would like sorted under "T" instead of "C" by using a tweak.

# Control title and series sorting in the library view. # If set to 'library_order', Leading articles such as The and A will be ignored.
 # If set to 'strictly_alphabetic', the titles will be sorted without processing
 # For example, with library_order, The Client will sort under 'C'. With
 # strictly_alphabetic, the book will sort under 'T'.
 # This flag affects Calibre's library display. It has no effect on devices. In
 # addition, titles for books added before changing the flag will retain their
 # order until the title is edited. Double-clicking on a title and hitting return
 # without changing anything is sufficient to change the sort.
 title_series_sorting = 'library_order'

Just change library_order to strictly_alphabetic.

You can also use this tweak to ensure it is presorted on startup.

# Provide a set of columns to be sorted on when calibre starts
#  The argument is None if saved sort history is to be used
#  otherwise it is a list of column,order pairs. Column is the
#  lookup/search name, found using the tooltip for the column
#  Order is 0 for ascending, 1 for descending
# For example, set it to [('authors',0),('title',0)] to sort by
# title within authors.

sort_columns_at_startup = ('authors',0),('series',0),('title',0)

This is the one I use.