mixguile: 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/mixguile - from package: mdk

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

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