lilysong: 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/lilysong - from package: lilypond

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

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