@@ -118,12 +118,20 @@
         section = composition[section]
         for subsection in ["intro", "body", "outro"]:
             try:
                 print "; Subsection " + subsection
                 subsection = section[subsection]
-                instrs = []
+                unordered_instrs = []
                 for instr in subsection:
+                    if not "sync" in subsection[instr]:
+                        subsection[instr]["sync"] = None
+                    unordered_instrs.append([subsection[instr]["sync"], instr])
+                ordered_instrs = topsort.topsort(unordered_instrs)
+                ordered_instrs.remove(None)
+                pdb.set_trace()
+                instrs = []
+                for instr in ordered_instrs:
                     print ";Instrument " + instr
                     instr = subsection[instr]
                     sync = None
                     max_time = instr["duration"]
                     instr_score = render_instr(instr, sync, max_time)