muse: 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/muse - from package: muse

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

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