playmidi: 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/playmidi - from package: playmidi

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

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