diff --git a/README.md b/README.md
index 7f5c045..50023d5 100644
--- a/README.md
+++ b/README.md
@@ -24,7 +24,7 @@ At the moment, an alpha version is undertaken, with these features:
 - Show possible commands (`h`)
 - Show mastered movements for activated user (`sm`)
 - display, if work or movement is mastered from active user when viewing works and movements
-- (planned) Works are shown sorted (opus, collection e.g. "Walzer", "Sonaten")
+- Works are shown sorted by composer and opus/work_directory-number (`s`, `smo`) or by composer and collection (`sm`)
 - (planned) Remove work or movement from being mastered for active user
 - (planned) Remove user
 - (planned) Fix known bugs
diff --git a/rep_cli.py b/rep_cli.py
index 4ff8637..85425d4 100644
--- a/rep_cli.py
+++ b/rep_cli.py
@@ -14,6 +14,7 @@ class Session:
                          'n': (self.create_new_user, 'Creates new user\n   Usage: n firstname name'),
                          's': (self.show_works, 'Show the works stored in the database\n   Usage: s, s number_of_composer'),
                          'sm': (self.show_mastered, 'Show mastered movements for activated user'),
+                         'smo': (self.show_mastered_opus, 'Show mastered movements for activated user, sorted by opus.'),
                          'sw': (self.show_movements, 'Show movements of a work\n   Usage: sw work_number'),
                          'su': (self.show_users, 'Show all users'),
                          'q': (self.quit, 'Quits the program')
@@ -104,7 +105,7 @@ class Session:
                 fun_resultstring += f'{key}: {value[1]}\n'
         return fun_resultstring
 
-    def show_mastered(self, _):
+    def show_mastered(self, _, key='standard'):
         fun_resultstring = 'Please activate user'
         if not self.user == -1:
             sql_command = f'''
@@ -118,7 +119,12 @@ class Session:
             for item in list_of_work_ids:
                 list_of_works.append(work_under_id(item[0], self.db_agent))
             fun_resultstring = 'All mastered movements:\n'
-            for work in sorted(list_of_works):
+            if key == 'opus':
+                list_of_works.sort(key=lambda work_s: work_s.opus_and_wd_for_comparison())
+            else:
+                list_of_works.sort(key=lambda work_s: work_s.sammlung())
+            list_of_works.sort()
+            for work in list_of_works:
                 for mov_number in work.values['movements'].keys():
                     # check if movement is mastered
                     sql_command = f'''
@@ -133,6 +139,9 @@ class Session:
                         fun_resultstring += f'{work.id()} {mov_number}. {work.pretty_mov(mov_number)}\n'
         return fun_resultstring
 
+    def show_mastered_opus(self, arguments):
+        return self.show_mastered(arguments, key='opus')
+
     def show_movements(self, arguments):
         work_id = arguments[0]
         work = work_under_id(work_id, self.db_agent)
@@ -171,7 +180,8 @@ class Session:
         for item in list_of_work_ids:
             list_of_works.append(work_under_id(item[0], self.db_agent))
         fun_resultstring = ''
-        for work in list_of_works:
+        list_of_works.sort(key=lambda wo: wo.opus_and_wd_for_comparison())
+        for work in sorted(list_of_works):
             mastered = self.percentage_of_work_is_mastered(work)
             if mastered == 100:
                 fun_resultstring += '[x] '
@@ -267,6 +277,22 @@ class work_under_id:
     def id(self):
         return self.values['id']
 
+    def just_num(self, st):
+        num_str = ''
+        for c in st:
+            if c.isdigit():
+                num_str += c
+        return int(num_str)
+
+    def opus_and_wd_for_comparison(self):
+        op = 9999 # no composer has that many!
+        if not self.values['opus'] is None:
+            op = self.just_num(self.values['opus'])
+        wd = 0 # no directory starts with 0
+        if not self.values['wd_number'] is None:
+            wd = self.just_num(self.values['wd_number'])
+        return (op, wd)
+
     def pretty_string(self):
         ret_str = ''
         for key in ['first_name', 'name',
@@ -317,8 +343,7 @@ class work_under_id:
         return ret_str
 
     def __lt__(self, other):
-        return ((self.values['name'], self.sammlung()) <
-                (other.values['name'], self.sammlung()))
+        return (self.values['name'] < other.values['name'])
 
 # End work_under_id