For an A to Z sort, on the MF screen use the 'G' button ('SORT ORDER') to select 'ASCENDING'. If this is set to 'DESCENDING' then the records will be displayed in a Z to A order.
You can also use the 'F' button ('SORT BY') to select the field (column) in the records that the sort is based on. This should be set to 'MUSIC' if you want a sort based on song name.
There is a short section 'Sorting the Records' on page 82 of the 'Tyros5 Owner's Manual' about sorting MF records. It may be worth reading it.
Regards
Ian