music-librarian: 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/music-librarian - from package: musiclibrarian

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

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