diff --git a/README.md b/README.md
index 9efeed5d..5ee064b9 100644
--- a/README.md
+++ b/README.md
@@ -171,8 +171,8 @@ copyparty can invoke external programs to collect additional metadata for files
 
 ## complete examples
 
-* read-only music server with bpm and key scanning
-* `python copyparty-sfx.py -v /mnt/nas/music:/music:r -e2dsa -e2ts -mtp .bpm=f,~/bin/audio-bpm.py -mtp key=f,~/bin/audio-key.py`
+* read-only music server with bpm and key scanning  
+  `python copyparty-sfx.py -v /mnt/nas/music:/music:r -e2dsa -e2ts -mtp .bpm=f,audio-bpm.py -mtp key=f,audio-key.py`
 
 
 # client examples
diff --git a/bin/mtag/README.md b/bin/mtag/README.md
index 464435e0..083b8fa9 100644
--- a/bin/mtag/README.md
+++ b/bin/mtag/README.md
@@ -6,3 +6,21 @@ some of these rely on libraries which are not MIT-compatible
 * [audio-key.py](./audio-key.py) detects the melodic key of music using the Mixxx fork of keyfinder; imports GPL3
 
 run [`install-deps.sh`](install-deps.sh) to build/install most dependencies required by these programs (supports windows/linux/macos)
+
+
+# usage from copyparty
+
+`copyparty -e2dsa -e2ts -mtp key=f,audio-key.py -mtp .bpm=f,audio-bpm.py`
+
+* `f,` makes the detected value replace any existing values
+* the `.` in `.bpm` indicates numeric value
+* assumes the python files are in the folder you're launching copyparty from, replace the filename with a relative/absolute path if that's not the case
+* `mtp` modules will not run if a file has existing tags in the db, so clear out the tags with `-e2tsr` the first time you launch with new `mtp` options
+
+
+## usage with volume-flags
+
+instead of affecting all volumes, you can set the options for just one volume like so:
+```
+copyparty -v /mnt/nas/music:/music:r:cmtp=key=f,audio-key.py:cmtp=.bpm=f,audio-bpm.py:ce2dsa:ce2ts
+```