easymp3gain-qt: 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/easymp3gain-qt - from package: easymp3gain-qt

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

Error in other languages:
easymp3gain-qt: bevel nie gevind nie
easymp3gain-qt: comandă negăsită
easymp3gain-qt: comando não encontrado
easymp3gain-qt: commande introuvable
easymp3gain-qt: command not found
easymp3gain-qt: käsku ei ole
easymp3gain-qt: không tìm thấy lệnh
easymp3gain-qt: komanda nerasta
easymp3gain-qt: Kommando nicht gefunden.
easymp3gain-qt: kommandot finns inte
easymp3gain-qt: komut yok
easymp3gain-qt: nie znaleziono polecenia
easymp3gain-qt: níor aimsíodh an t-ordú
easymp3gain-qt: no se encontró la orden
easymp3gain-qt: no s'ha trobat l'ordre
easymp3gain-qt: opdracht niet gevonden
easymp3gain-qt: parancs nem található
easymp3gain-qt: perintah tidak ditemukan
easymp3gain-qt: príkaz nenájdený
easymp3gain-qt: příkaz nenalezen
easymp3gain-qt: команда не найдена
easymp3gain-qt: командата не е открита
easymp3gain-qt: 命令找不到
easymp3gain-qt: コマンドが見つかりません