Amarok 2 can search through music collection using ID3v2 tag's 'bpm' field. That would be very nice to retag the entire music collection so I can find the 'mood' of the track I like.

However I've not found any beat-detection software that could have helped me. Have you ever used one? CLI, preferably. Also I'm interested if there's anything alike for tagging FLACs with the same 'bpm' field.

Thanks! :)

P.S. I'm aware there's a nice moodbar feature, however it's useless for searching.


9 Answers 9


At the site DaveParillo suggested I've found BpmDj project. It has a bpmcount executable that calculates the bpm very nice: it handles mp3 as well as flac:

161.135 Metallica/2008 - Death Magnetic/01-That Was Just Your Life.flac
63.5645 Doom3.mp3

The only thing that's left is to retag the collection. I'll update this answer whenever I succeed. Thanks! :)

Step 1

Run bpmcount against the entire collection and store the results into a textfile. The problem is that bpmcount crashes from time to time and tries to eat up to 2GB of memory when it processes several files so we should feed it with filenames one by one. Like this:

find "$musicdir" -iregex ".*\.\(mp3\|ogg\|flac\|ape\)" -exec bpmcount {} \; \
    | fgrep "$musicdir" > "$musicdir/BPMs.txt"

Step 2

We'll need some additional packages: apt-get install vorbis-tools flac python-mutagen. Now have a look at how the 'bpm' tag can be added:

mid3v2 --TBPM 100 doom3.mp3
vorbiscomment -a -t "BPM=100" mother.ogg
metaflac --set-tag="BPM=100" metallica.flac

Alas, I have no *.ape tracks

Now we have the BPMs and the entire collection should be retagged. Here's the script:

cat "$musicdir/BPMs.txt" | while read bpm file ; do
    bpm=`printf "%.0f" "$bpm"` ;
    case "$file" in 
        *.mp3) mid3v2 --TBPM "$bpm" "$file" > /dev/null ;; 
        *.ogg) vorbiscomment -a -t "BPM=$bpm" "$file" ;; 
        *.flac) metaflac --set-tag="BPM=$bpm" "$file" ;; 

Step 2.1 Revisited Here's a script that will add BPM tags to your collection.

It runs one process per CPU Core to make the process faster. Additionally, it uses no temporary files and it capable of detecting whether a file is already tagged.

Additionally, I've discovered that FLAC sometimes has both ID3 and VorbisComment inside. This script updates both.


function display_help() {
    cat <<-HELP
            Recursive BPM-writer for multicore CPUs.
            It analyzes BPMs of every media file and writes a correct tag there.
            Usage: $(basename "$0") path [...]
    exit 0

[ $# -lt 1 ] && display_help

#=== Requirements
requires="bpmcount mid3v2 vorbiscomment metaflac"
which $requires > /dev/null || { echo "E: These binaries are required: $requires" >&2 ; exit 1; }

#=== Functions

function bpm_read(){
    local file="$1"
    local ext="${file##*.}"
    declare -l ext
    # Detect
    { case "$ext" in
        'mp3')  mid3v2 -l "$file" ;;
        'ogg')  vorbiscomment -l "$file" ;;
        'flac') metaflac --export-tags-to=- "$file" ;;
        esac ; } | fgrep 'BPM=' | cut -d'=' -f2
function bpm_write(){
    local file="$1"
    local bpm="${2%%.*}"
    local ext="${file##*.}"
    declare -l ext
    echo "BPM=$bpm @$file"
    # Write
    case "$ext" in
        'mp3')  mid3v2 --TBPM "$bpm" "$file" ;;
        'ogg')  vorbiscomment -a -t "BPM=$bpm" "$file" ;;
        'flac') metaflac --set-tag="BPM=$bpm" "$file"
                mid3v2 --TBPM "$bpm" "$file" # Need to store to ID3 as well :(

#=== Process
function oneThread(){
    local file="$1"
    #=== Check whether there's an existing BPM
        local bpm=$(bpm_read "$file")
        [ "$bpm" != '' ] && return 0 # there's a nonempty BPM tag
    #=== Detect a new BPM
    # Detect a new bpm
    local bpm=$(bpmcount "$file" | grep '^[0-9]' | cut -f1)
    [ "$bpm" == '' ] && { echo "W: Invalid BPM '$bpm' detected @ $file" >&2 ; return 0 ; } # problems
    # Write it
    bpm_write "$file" "${bpm%%.*}" >/dev/null

NUMCPU="$(grep ^processor /proc/cpuinfo | wc -l)"
find $@ -type f -regextype posix-awk -iregex '.*\.(mp3|ogg|flac)' \
    | while read file ; do
        [ `jobs -p | wc -l` -ge $NUMCPU ] && wait
        echo "$file"
        oneThread "$file" &

Enjoy! :)

  • Excellent! I hadn't gotten around to trying this last night. As far as command line tagging, try mid3v2: linux.die.net/man/1/mid3v2, serviceable at least until Ex Falso supports command line editing. The id3v2 tad id is TBPM Apr 9, 2010 at 16:24
  • 1
    Thanks, I'll try in a couple of days and post the results :) I wonder whether FLAC supports such thing: I'll have to check this out.
    – kolypto
    Apr 9, 2010 at 19:51
  • 1
    Nice work on step #2. Wish I could upvote twice! Apr 12, 2010 at 4:31
  • 1
    Thanks :) Alas, my Amarok didn't notice the new tag in FLACs which I like the most :)) bug submitted.
    – kolypto
    Apr 12, 2010 at 15:36
  • How did you install it? the rpm they provide doesn't seem to work in my computer and I am struggling with the compilation. Jul 25, 2012 at 18:56

This is a command-line tool to detect the BPM and put it in the FLAC file tags:


  • The latest version also handles mp3s and ogg vorbis.
    – encoded
    Jan 10, 2013 at 20:51
  • 1
    Ubuntu has bpm-tools packages available in saucy.
    – naught101
    Apr 5, 2014 at 6:44

I used kolypto's original script using bpmcount and rewrote it for bpm-tag (utility of bpm-tools) which I had better luck with installing. I also made some improvements of my own.

You can find it on GitHub https://github.com/meridius/bpmwrap

  • This required a few modifications to work on a Mac, which I have included in my own answer below (because it is too long for a comment)
    – Adrian
    Nov 17, 2016 at 23:14

I don't know of a tool that does exactly what you are looking for, but I have played around with MusicIP.

Used the linux / java version - it takes a long time to completely analyze a music library, but it really does work. You can find songs that are similar to other songs. You can right click on the playlist generated and select option to select more or fewer songs like the one selected. You can also choose to eliminate certain genre's. It's kind of cool, but after the wow factor wore off, I stopped using it.

The free version exports playlists up to 75 songs in (at least) m3u format.

It's currently unsupported, but I think they have tried to take it commercial as Predexis.


There is another tool recommended in this question on stackoverflow: aubio, which comes along with python modules.

I haven't tried it because I was kinda busy taking care of compiling BpmDj. Just in case anybody else finds themselves struggling similar troubles while trying, I'd like to strongly recommend to make absolutely sure:

  1. having downloaded the latest release of the BpmDj sources
  2. having the appropriate boost libraries installed

With the latest g++ compiler upgrades, some issues seem to have arisen especially concerning recent debian and ubuntu releases. As soon as he became aware of these problems, the author had the kindness to fix the emerged incompatibilities and put together a new release which now compiles like a charm. So anybody who have been close to falling into despair over relentless compile errors lately: you are save now.

@mmx, your tools look good too, but they rely on SoX, which by default has no mp3 features. So they require compiling SoX with Lame/MAD support first, which unfortunately is too much effort for people as lazy as me.


While it is not just a tool like you say you are looking for, Banshee media player can detect bpm.

I use Banshee for all my music playing, organisation and synchronizing to portable players. I'm not affiliated, but I like the program the best of all that I've tried. It can also generate "smart playlists" based on all sorts of properties of the tracks, including bpm.

There is an extension which analyses all sorts of things about the song, and will find similar songs to the one you're playing. It's called Mirage, and I used it for a while, but I don't any more, as I've created a number of playlists of ones that suit various moods (not necessarily similar according to Mirage).

I don't know if Banshee will save the bpm it detected back into the ID3v2 "bpm" tag of the file. If anyone knows how to easily check the bpm tag from outside the program I'll check.


It's not Linux but may well work in Wine - I use MixMeister BPM Analyzer


I found another tool for tagging MP3 files with the correct BPM value.

It's called BPMDetect. Open-source. QT libs so works fine under Gnome. Comes with a GUI but can be compiled as a console only version (run "scons console=1" as stated in the readme.txt).

Otherwise, in the end, i've too used the "bpmcount" from BpmDJ as i had difficulties to compile BPMDetect on a 64 bits Ubuntu host (due to the fmodex dependency). So i took the (very cool and well-written) shell script above (see below), the "bpmcount" binary extracted from the [x64 .rpm][3] available on the BpmDJ website (i've just extract the .rpm with

pm2cpio bpmdj-4.2.pl2-0.x86_64.rpm|cpio -idv

and it worked like a charm. I just had to modify the above script as, out of the box, it weren't working on my side (problem with stdout / stderr of the bpmcount binary). My modification is about file redirection :

local bpm=$(bpmcount "$file" 3>&1 1>/dev/null 2>&3 | grep '^[0-9]' | cut -f1)

To get @meridius' solution working on my Mac I had to do a bit of extra legwork and modify the script a bit:

# Let's install bpm-tools
git clone http://www.pogo.org.uk/~mark/bpm-tools.git
cd bpm-tools
make && make install
# There will be errors, but they did not affect the result

# The following three lines could be replaced by including this directory in your $PATH
ln -s <absolute path to bpm-tools>/bpm /usr/local/bin/bpm
ln -s <absolute path to bpm-tools>/bpm-tag /usr/local/bin/bpm-tag
ln -s <absolute path to bpm-tools>/bpm-graph /usr/local/bin/bpm-graph
cd ..

# Time to install a bunch of GNU tools
# Not all of these packages are strictly necessary for this script, but I decided I wanted the whole GNU toolchain in order to avoid this song-and-dance in the future
brew install coreutils findutils gnu-tar gnu-sed gawk gnutls gnu-indent gnu-getopt bash flac vorbis-tools
brew tap homebrew/dupes; brew install grep

# Now for Mutagen (contains mid3v2)
git clone https://github.com/nex3/mutagen.git
cd mutagen
./setup.py build
sudo ./setup.py install
# There will be errors, but they did not affect the result
cd ..

Then I had to modify the script to point to the GNU versions of everything, and a few other tweaks:


# ================================= FUNCTIONS =================================

function help() {
    less <<< 'BPMWRAP

    This BASH script is a wrapper for bpm-tag utility of bpm-tools and several
    audio tagging utilities. The purpose is to make BPM (beats per minute)
    tagging as easy as possible.
    Default behaviour is to look through working directory for *.mp3 files
    and compute and print their BPM in the following manner:
        [current (if any)] [computed] [filename]

    bpmwrap [options] [directory or filenames]

    You can specify files to process by one of these ways:
        1) state files and/or directories containing them after options
        2) specify --import file
        3) specify --input file
    With either way you still can filter the resulting list using --type option(s).
    Remember that the script will process only mp3 files by default, unless
    specified otherwise!

    -i, --import file
        Use this option to set BPM tag for all files in given file instead of
        computing it. Expected format of every row is BPM number and absolute path
        to filename separated by semicolon like so:
            145;/home/trinity/music/Apocalyptica/07 beyond time.mp3
        Remember to use --write option too.
    -n, --input file
        Use this option to give the script list of FILES to process INSTEAD of paths
        where to look for them. Each row whould have one absolute path.
        This will bypass the searching part and is that way useful when you want
        to process large number of files several times. Like when you are not yet
        sure what BPM limits to set. Extension filtering will still work.
    -o, --output file
        Save output also to a file.
    -l, --list-save file
        Save list of files about to get processed. You can use this list later
        as a file for --input option.
    -t, --type filetype
        Extension of file type to work with. Defaults to mp3. Can be specified
        multiple times for more filetypes. Currently supported are mp3 ogg flac.
    -e, --existing-only
        Only show BPM for files that have it. Do NOT compute new one.
    -w, --write
        Write computed BPM to audio file but do NOT overwrite existing value.
    -f, --force
        Write computed BPM to audio file even if it already has one. Aplicable only
        with --write option.
    -m, --min minbpm
        Set minimal BPM to look for when computing. Defaults to bpm-tag minimum 84.
    -x, --max maxbpm
        Set maximal BPM to look for when computing. Defaults to bpm-tag maximum 146.
    -v, --verbose
        Show "progress" messages.
    -c, --csv-friendly
        Use semicolon (;) instead of space to separate output columns.
    -h, --help
        Show this help.

    Program bpm-tag (on whis is this script based) is looking only for lowercase
    file extensions. If you get 0 (zero) BPM, this should be the case. So just
    rename the file.

    GPL V2

    bpm-tools (http://www.pogo.org.uk/~mark/bpm-tools/)

    bpm-tag mid3v2 vorbiscomment metaflac

    Martin Lukeš ([email protected])
    Based on work of kolypto (http://superuser.com/a/129157/137326)

# Usage: result=$(inArray $needle haystack[@])
# @param string needle
# @param array haystack
# @returns int (1 = NOT / 0 = IS) in array
function inArray() {
    for e in "${haystack[@]}" ; do
        if [[ "$e" = "$needle" ]] ; then
    echo $out

# Usage: result=$(implode $separator array[@])
# @param char separator
# @param array array to implode
# @returns string separated array elements
function implode() {
    echo "${array[*]}"

# @param string file
# @returns int BPM value
function getBpm() {
    local file="$1"
    local ext="${file##*.}"
    declare -l ext # convert to lowercase
    { case "$ext" in
        'mp3')  mid3v2 -l "$file" ;;
        'ogg')  vorbiscomment -l "$file" ;;
        'flac') metaflac --export-tags-to=- "$file" ;;
    esac ; } | fgrep 'BPM=' -a | cut -d'=' -f2

# @param string file
# @param int BPM value
function setBpm() {
    local file="$1"
    local bpm="${2%%.*}"
    local ext="${file##*.}"
    declare -l ext # convert to lowercase
    case "$ext" in
        'mp3')  mid3v2 --TBPM "$bpm" "$file" ;;
        'ogg')  vorbiscomment -a -t "BPM=$bpm" "$file" ;;
        'flac') metaflac --set-tag="BPM=$bpm" "$file"
            mid3v2 --TBPM "$bpm" "$file" # Need to store to ID3 as well :(

# # @param string file
# # @returns int BPM value
function computeBpm() {
    local file="$1"
    local m_opt=""
    [ ! -z "$m" ] && m_opt="-m $m"
    local x_opt=""
    [ ! -z "$x" ] && x_opt="-x $x"
    local row=$(bpm-tag -fn $m_opt $x_opt "$file" 2>&1 | fgrep "$file")
    echo $(echo "$row" \
        | gsed -r 's/.+ ([0-9]+\.[0-9]{3}) BPM/\1/' \
        | gawk '{printf("%.0f\n", $1)}')

# @param string file
# @param int file number
# @param int BPM from file list given by --import option
function oneThread() {
    local file="$1"
    local filenumber="$2"
    local bpm_hard="$3"
    local bpm_old=$(getBpm "$file")
    [ -z "$bpm_old" ] && bpm_old="NONE"
    if [ "$e" ] ; then # only show existing
        myEcho "$filenumber/$NUMFILES${SEP}$bpm_old${SEP}$file"
    else # compute new one
        if [ "$bpm_hard" ] ; then
            local bpm_new="$bpm_hard"
            local bpm_new=$(computeBpm "$file")
        [ "$w" ] && { # write new one
            if [[ ! ( ("$bpm_old" != "NONE") && ( -z "$f" ) ) ]] ; then
                setBpm "$file" "$bpm_new"
                [ "$v" ] && myEcho "Non-empty old BPM value, skipping ..."
        myEcho "$filenumber/$NUMFILES${SEP}$bpm_old${SEP}$bpm_new${SEP}$file"

function myEcho() {
    [ "$o" ] && echo -e "$1" >> "$o"
    echo -e "$1"

# ================================== OPTIONS ==================================

eval set -- $(/usr/local/Cellar/gnu-getopt/1.1.6/bin/getopt -n $0 -o "-i:n:o:l:t:ewfm:x:vch" \
    -l "import:,input:,output:,list-save:,type:,existing-only,write,force,min:,max:,verbose,csv-friendly,help" -- "$@")

declare i n o l t e w f m x v c h
declare -a INPUTFILES
declare -a INPUTTYPES
while [ $# -gt 0 ] ; do
    case "$1" in
        -i|--import)                shift ; i="$1" ; shift ;;
        -n|--input)                 shift ; n="$1" ; shift ;;
        -o|--output)                shift ; o="$1" ; shift ;;
        -l|--list-save)         shift ; l="$1" ; shift ;;
        -t|--type)                  shift ; INPUTTYPES=("${INPUTTYPES[@]}" "$1") ; shift ;;
        -e|--existing-only) e=1 ; shift ;;
        -w|--write)                 w=1 ; shift ;;
        -f|--force)                 f=1 ; shift ;;
        -m|--min)                       shift ; m="$1" ; shift ;;
        -x|--max)                       shift ; x="$1" ; shift ;;
        -v|--verbose)               v=1 ; shift ;;
        -c|--csv-friendly)  c=1 ; shift ;;
        -h|--help)                  h=1 ; shift ;;
        --)                                 shift ;;
        -*)                                 echo "bad option '$1'" ; exit 1 ;; #FIXME why this exit isn't fired?
        *)                                  INPUTFILES=("${INPUTFILES[@]}" "$1") ; shift ;;

# ================================= DEFAULTS ==================================

#NOTE Remove what requisities you don't need but don't try to use them after!
#         always  mp3/flac     ogg       flac
REQUIRES="bpm-tag mid3v2 vorbiscomment metaflac"
which $REQUIRES > /dev/null || { myEcho "These binaries are required: $REQUIRES" >&2 ; exit 1; }

[ "$h" ] && {
    exit 0

[[ $m && $x && ( $m -ge $x ) ]] && {
    myEcho "Minimal BPM can't be bigger than NOR same as maximal BPM!"
    exit 1
[[ "$i" && "$n" ]] && {
    echo "You cannot specify both -i and -n options!"
    exit 1
[[ "$i" && ( "$m" || "$x" ) ]] && {
    echo "You cannot use -m nor -x option with -i option!"
    exit 1
[ "$e" ] && {
    [[ "$w" || "$f" ]] && {
        echo "With -e option you don't have any value to write!"
        exit 1
    [[ "$m" || "$x" ]] && {
        echo "With -e option you don't have any value to count!"
        exit 1

for file in "$o" "$l" ; do
    if [ -f "$file" ] ; then
        while true ; do
            read -n1 -p "Do you want to overwrite existing file ${file}? (Y/n): " key
            case "$key" in
                y|Y|"") echo "" > "$file" ; break ;;
                n|N)        exit 0 ;;
            echo ""
        echo ""

[ ${#INPUTTYPES} -eq 0 ] && INPUTTYPES=("mp3")

# NUMCPU="$(ggrep ^processor /proc/cpuinfo | wc -l)"
NUMCPU="$(sysctl -a | ggrep machdep.cpu.core_count | gsed -r 's/(.*)([0-9]+)(.*)/\2/')"
TYPESALLOWED=("mp3" "ogg" "flac")
# declare -A BPMIMPORT # array of BPMs from --import file, keys are file names
declare -A BPMIMPORT # array of BPMs from --import file, keys are file names

for type in "${INPUTTYPES[@]}" ; do
    [[ $(inArray $type TYPESALLOWED[@]) -eq 1 ]] && {
        myEcho "Filetype $type is not one of allowed types (${TYPESALLOWED[@]})!"
        exit 1

### here are three ways how to pass files to the script...
if [ "$i" ] ; then # just parse given file list and set BPM to listed files
    if [ -f "$i" ] ; then
        # myEcho "Setting BPM tags from given file ..."
        while read row ; do
            ext="${ext,,}" # convert to lowercase
            if [ -f "$file" ] ; then
                if [ $(inArray $ext INPUTTYPES[@]) -eq 0 ] ; then
                    FILES=("${FILES[@]}" "$file")
                    myEcho "Skipping file on row $rownumber (unwanted filetype $ext) ... $file"
                myEcho "Skipping non-existing file $file"
        done < "$i"
        myEcho "Given import file does not exists!"
        exit 1
elif [ "$n" ] ; then # get files from file list
    if [ -f "$n" ] ; then
        while read file ; do
            if [ -f "$file" ] ; then
                ext="${ext,,}" # convert to lowercase
                if [ $(inArray $ext INPUTTYPES[@]) -eq 0 ] ; then
                    FILES=("${FILES[@]}" "$file")
                    myEcho "Skipping file on row $rownumber (unwanted filetype $ext) ... $file"
                myEcho "Skipping file on row $rownumber (non-existing) ... $file"
            let rownumber++
        done < "$n"
        unset rownumber
        myEcho "Given input file $n does not exists!"
        exit 1
else # get files from given parameters
    [ ${#INPUTFILES[@]} -eq 0 ] && INPUTFILES=`pwd`
    for file in "${INPUTFILES[@]}" ; do
        [ ! -e "$file" ] && {
            myEcho "File or directory $file does not exist!"
            exit 1
    impl_types=`implode "|" INPUTTYPES[@]`
    while read file ; do
        echo -ne "Creating list of files ... (${#FILES[@]}) ${file}\033[0K"\\r
        FILES=("${FILES[@]}" "$file")
    done < <(gfind "${INPUTFILES[@]}" -type f -regextype posix-awk -iregex ".*\.($impl_types)")
    echo -e "Counted ${#FILES[@]} files\033[0K"\\r

[ "$l" ] && printf '%s\n' "${FILES[@]}" > "$l"


[ $NUMFILES -eq 0 ] && {
    myEcho "There are no ${INPUTTYPES[@]} files in given files/paths."
    exit 1

declare SEP=" "
[ "$c" ] && SEP=";"

# =============================== MAIN SECTION ================================

if [ "$e" ] ; then # what heading to show
    myEcho "num${SEP}old${SEP}filename"
    myEcho "num${SEP}old${SEP}new${SEP}filename"

for file in "${FILES[@]}" ; do
    [ `jobs -p | wc -l` -ge $NUMCPU ] && wait
    [ "$v" ] && myEcho "Parsing (${FILENUMBER}/${NUMFILES})\t$file ..."
    oneThread "$file" "$FILENUMBER" "${BPMIMPORT[$file]}" &
    let FILENUMBER++

[ "$v" ] && myEcho "Waiting for last process ..."
[ "$v" ] && myEcho \\n"DONE"

Thank you for your hard work @kolypto and @meridius.

...the pain I go through to maintain a CLI workflow and pay no money for music tools...

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