diff --git a/miditoolkit/midi/containers.py b/miditoolkit/midi/containers.py
index 19767b2..bf78592 100755
--- a/miditoolkit/midi/containers.py
+++ b/miditoolkit/midi/containers.py
@@ -295,16 +295,16 @@ def remove_invalid_notes(self, verbose: bool = True) -> None:
 
     def remove_notes_with_no_duration(self) -> None:
         """Removes (inplace) notes whose end time is before or at their start time."""
-        for i in range(self.nb_notes - 1, -1, -1):
+        for i in range(self.num_notes - 1, -1, -1):
             if self.notes[i].start >= self.notes[i].end:
                 del self.notes[i]
 
     @property
-    def nb_notes(self) -> int:
+    def num_notes(self) -> int:
         return len(self.notes)
 
     def __repr__(self):
-        return f"Instrument(program={self.program}, is_drum={self.is_drum}, name={self.name}) - {self.nb_notes} notes"
+        return f"Instrument(program={self.program}, is_drum={self.is_drum}, name={self.name}) - {self.num_notes} notes"
 
     def __eq__(self, other):
         # Here we check all tracks attributes except the name.
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 467cae6..1ca2872 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -12,7 +12,7 @@ def test_remove_notes_with_no_duration(midi_path, tmp_path):
     # Load the MIDI file and removes the notes with durations <= 0
     midi = MidiFile(midi_path)
     midi.instruments[0].remove_notes_with_no_duration()
-    nb_notes_before = midi.instruments[0].nb_notes
+    num_notes_before = midi.instruments[0].num_notes
 
     # Adding notes with durations <= 0, then reapply the method
     midi.instruments[0].notes.append(Note(50, 50, 100, 100))
@@ -20,5 +20,5 @@ def test_remove_notes_with_no_duration(midi_path, tmp_path):
     midi.instruments[0].remove_notes_with_no_duration()
 
     assert (
-        midi.instruments[0].nb_notes == nb_notes_before
+        midi.instruments[0].num_notes == num_notes_before
     ), "The notes with duration <=0 were not removed by test_remove_notes_with_no_duration"