pianobar: 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/pianobar - from package: pianobar

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

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