Update app.py

app.py

@@ -70,8 +70,8 @@ def compress_files(demucs_output_path, dissector_file, original_audio):
     with ThreadPoolExecutor(max_workers=8) as executor:
         list(executor.map(convert_to_mp3, wav_files, mp3_files))
 
-    if not os.path.exists(basic_pitch_dir):
-        os.makedirs(basic_pitch_dir)
+    if not os.path.exists(BASIC_PITCH_DIR):
+        os.makedirs(BASIC_PITCH_DIR)
     command = [
         "basic-pitch",
         BASIC_PITCH_DIR,