diff --git a/copyparty/authsrv.py b/copyparty/authsrv.py
index 557d1333..28f649fc 100644
--- a/copyparty/authsrv.py
+++ b/copyparty/authsrv.py
@@ -475,8 +475,10 @@ class AuthSrv(object):
             # verify tags mentioned by -mt[mp] are used by -mte
             local_mtp = {}
             local_only_mtp = {}
-            for a in vol.flags.get("mtp", []) + vol.flags.get("mtm", []):
-                a = a.split("=")[0]
+            tags = vol.flags.get("mtp", []) + vol.flags.get("mtm", [])
+            tags = [x.split("=")[0] for x in tags]
+            tags = [y for x in tags for y in x.split(",")]
+            for a in tags:
                 local_mtp[a] = True
                 local = True
                 for b in self.args.mtp or []:
diff --git a/copyparty/mtag.py b/copyparty/mtag.py
index 79258d1d..2de74435 100644
--- a/copyparty/mtag.py
+++ b/copyparty/mtag.py
@@ -4,6 +4,7 @@ from __future__ import print_function, unicode_literals
 import re
 import os
 import sys
+import json
 import shutil
 import subprocess as sp
 
@@ -394,8 +395,16 @@ class MTag(object):
 
                 cmd = [fsenc(x) for x in cmd]
                 v = sp.check_output(cmd, **args).strip()
-                if v:
+                if not v:
+                    continue
+
+                if "," not in tagname:
                     ret[tagname] = v.decode("utf-8")
+                else:
+                    v = json.loads(v)
+                    for tag in tagname.split(","):
+                        if tag and tag in v:
+                            ret[tag] = v[tag]
             except:
                 pass
 
diff --git a/copyparty/up2k.py b/copyparty/up2k.py
index 9fd7c9ee..085f5eae 100644
--- a/copyparty/up2k.py
+++ b/copyparty/up2k.py
@@ -533,7 +533,13 @@ class Up2k(object):
         for parser in self.flags[ptop]["mtp"]:
             orig = parser
             tag, parser = parser.split("=", 1)
-            if tag not in entags:
+
+            skip = False
+            for t in tag.split(","):
+                if t and t not in entags:
+                    skip = True
+
+            if skip:
                 continue
 
             audio[tag] = "y"
@@ -683,8 +689,8 @@ class Up2k(object):
         entags = self.entags[ptop]
         parsers = {}
         for k, v in all_parsers.items():
-            if ".dur" in entags:
-                if ".dur" in have:
+            if "ac" in entags or ".aq" in entags:
+                if "ac" in have or ".aq" in have:
                     # is audio, require non-audio?
                     if audio[k] == "n":
                         continue
@@ -701,6 +707,9 @@ class Up2k(object):
         # mp.pool.ThreadPool and concurrent.futures.ThreadPoolExecutor
         # both do crazy runahead so lets reinvent another wheel
         nw = os.cpu_count() if hasattr(os, "cpu_count") else 4
+        if self.args.no_mtag_mt:
+            nw = 1
+
         if self.pending_tags is None:
             self.log("using {}x {}".format(nw, self.mtag.backend))
             self.pending_tags = []