mp3cut: 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/mp3cut - from package: poc-streamer

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

Error in other languages:
mp3cut: bevel nie gevind nie
mp3cut: comandă negăsită
mp3cut: comando não encontrado
mp3cut: commande introuvable
mp3cut: command not found
mp3cut: käsku ei ole
mp3cut: không tìm thấy lệnh
mp3cut: komanda nerasta
mp3cut: Kommando nicht gefunden.
mp3cut: kommandot finns inte
mp3cut: komut yok
mp3cut: nie znaleziono polecenia
mp3cut: níor aimsíodh an t-ordú
mp3cut: no se encontró la orden
mp3cut: no s'ha trobat l'ordre
mp3cut: opdracht niet gevonden
mp3cut: parancs nem található
mp3cut: perintah tidak ditemukan
mp3cut: príkaz nenájdený
mp3cut: příkaz nenalezen
mp3cut: команда не найдена
mp3cut: командата не е открита
mp3cut: 命令找不到
mp3cut: コマンドが見つかりません