mp3info: 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/mp3info - from package: mp3info

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

Error in other languages:
mp3info: bevel nie gevind nie
mp3info: comandă negăsită
mp3info: comando não encontrado
mp3info: commande introuvable
mp3info: command not found
mp3info: käsku ei ole
mp3info: không tìm thấy lệnh
mp3info: komanda nerasta
mp3info: Kommando nicht gefunden.
mp3info: kommandot finns inte
mp3info: komut yok
mp3info: nie znaleziono polecenia
mp3info: níor aimsíodh an t-ordú
mp3info: no se encontró la orden
mp3info: no s'ha trobat l'ordre
mp3info: opdracht niet gevonden
mp3info: parancs nem található
mp3info: perintah tidak ditemukan
mp3info: príkaz nenájdený
mp3info: příkaz nenalezen
mp3info: команда не найдена
mp3info: командата не е открита
mp3info: 命令找不到
mp3info: コマンドが見つかりません