fix: guitar too loud in music

app.py

@@ -347,6 +347,8 @@ def combine_stems_for_all(input_dir, output_format="mp3"):
 
         # Load and combine stems
         stems = {name: AudioSegment.from_file(path) for name, path in stem_paths.items()}
+
+        stems["instrumental"] = stems["instrumental"].apply_gain(-15)
         combined = stems["vocals"].overlay(stems["bass"]).overlay(stems["others"]).overlay(stems["instrumental"])
 
         # Trim silence at the end