move vocals to post-processing

app.py

@@ -80,15 +80,13 @@ if st.button("Generate Audio") and genre and energy_level and description and te
     sample_rate = response.json()[0]['sample_rate']
     st.audio(st_state.audio, format="audio/wav", sample_rate=sample_rate, start_time=0)
 
- 
-vocal_file = st.file_uploader("Upload Vocal File", type=["mp3", "wav", "ogg", "flac", "aac"])
+# Post-processing options
+st.header("Post-processing Options")
 
+vocal_file = st.file_uploader("Upload Vocal File", type=["mp3", "wav", "ogg", "flac", "aac"])
 if vocal_file:
     st_state.vocal_audio = vocal_file.read()
     
-# Post-processing options
-st.header("Post-processing Options")
-
 # Mixing
 mix_vocals = st.checkbox("Mix Vocals")
 if mix_vocals and st_state.vocal_audio is not None: