aubiopitch: 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/aubiopitch - from package: aubio-tools

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

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