diff --git a/setclass/setclass.py b/setclass/setclass.py
index aeead6b..7aedbab 100644
--- a/setclass/setclass.py
+++ b/setclass/setclass.py
@@ -61,7 +61,7 @@ class SetClass(list):
         return sum([hash(i) for i in self.pitch_classes])
 
     @property
-    def pitch_classes(self) -> list:
+    def pitch_classes(self) -> list(int):
         return list(self)
 
     @cache_property
@@ -83,7 +83,7 @@ class SetClass(list):
         return sum(self.pitch_classes)
 
     @cache_property
-    def adjacency_intervals(self) -> list:
+    def adjacency_intervals(self) -> list(int):
         """Adjacency intervals between the pitch classes, used for Leonard notation subscripts."""
         if not self.pitch_classes:
             return list()
@@ -138,7 +138,7 @@ class SetClass(list):
         return min(SetClass.ordered_interval(a, b), SetClass.ordered_interval(b, a))
 
     @cache_property
-    def versions(self) -> list:
+    def versions(self) -> list(SetClass):
         """
         Returns all possible zero-normalised versions (clock rotations) of this set class,
         sorted by brightness. See Rahn (1980) Set types, Tₙ
@@ -309,12 +309,12 @@ class SetClass(list):
     # Class methods -----------------------------------------------------------
 
     @classmethod
-    def from_string(this, string: str) -> SetClass:
+    def from_string(this, string: str, tonality: int = 12) -> SetClass:
         """
         Attempt to create a SetClass from any string containing a sequence of zero or more integers.
         A useful convenience function, e.g. SetClass.from_string('{0,3,7,9}')
         """
-        return SetClass(*re.findall(r'\d+', string))
+        return SetClass(*re.findall(r'\d+', string), tonality=tonality)
 
     @classmethod
     def all_of_cardinality(cls, cardinality: int, tonality: int = 12) -> set:
@@ -363,7 +363,7 @@ class SetClass(list):
         """
         cases = set()
         for C in range(13):  # 0 to 12
-            for sc in SetClass.all_of_cardinality(C):
+            for sc in this.all_of_cardinality(C):
                 if sc.darkest_form.brightness < sc.rahn_normal_form.brightness:
                     cases.add((C, sc.darkest_form, sc.rahn_normal_form))
         return cases
@@ -379,7 +379,7 @@ class SetClass(list):
         """
         cases = set()
         for C in range(13):  # 0 to 12
-            for sc in SetClass.all_of_cardinality(C):
+            for sc in this.all_of_cardinality(C):
                 if sc.darkest_form.brightness < sc.prime_form.brightness:
                     cases.add((C, sc.darkest_form, sc.prime_form))
         return cases