Update app.py

app.py

@@ -204,17 +204,21 @@ def MixMelody(input_midi, input_find_best_match):
             
             if trg_patch in patches:
 
-                if midx < len(src_melody):
+                if midx < len(src_melody)-1:
                     next_note_dtime = src_melody[midx+1][1] - src_melody[midx][1]
-                
+                else:
+                    next_note_dtime = 255
+                    
                 mixed_song.extend(mix_chord(c, src_harm_tones_chords[midx], trg_patch, src_melody_pitches[midx], next_note_dtime))
                 
                 midx += 1
             
             else:
 
-                if i < len(cscore):
+                if i < len(cscore)-1:
                     next_note_dtime = cscore[i+1][0][1] - cscore[i][0][1]
+                else:
+                    next_note_dtime = 255
                 
                 mixed_song.extend(mix_chord(cho, src_harm_tones_chords[midx], trg_patch, src_melody_pitches[midx], next_note_dtime))