cmus-remote: 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/cmus-remote - from package: cmus

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

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