tagmp3: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/tagmp3 - from package: mpgtx

You may install the required package with command apt-get install {package}

Error in other languages:
tagmp3: bevel nie gevind nie
tagmp3: comandă negăsită
tagmp3: comando não encontrado
tagmp3: commande introuvable
tagmp3: command not found
tagmp3: käsku ei ole
tagmp3: không tìm thấy lệnh
tagmp3: komanda nerasta
tagmp3: Kommando nicht gefunden.
tagmp3: kommandot finns inte
tagmp3: komut yok
tagmp3: nie znaleziono polecenia
tagmp3: níor aimsíodh an t-ordú
tagmp3: no se encontró la orden
tagmp3: no s'ha trobat l'ordre
tagmp3: opdracht niet gevonden
tagmp3: parancs nem található
tagmp3: perintah tidak ditemukan
tagmp3: príkaz nenájdený
tagmp3: příkaz nenalezen
tagmp3: команда не найдена
tagmp3: командата не е открита
tagmp3: 命令找不到
tagmp3: コマンドが見つかりません