lmms: 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/lmms - from package: lmms

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

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