id3convert: 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 CentOS possible default full paths are:

/usr/bin/id3convert - from package: id3lib

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/id3convert - from package: libid3-tools

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

Error in other languages:
id3convert: bevel nie gevind nie
id3convert: comandă negăsită
id3convert: comando não encontrado
id3convert: commande introuvable
id3convert: command not found
id3convert: käsku ei ole
id3convert: không tìm thấy lệnh
id3convert: komanda nerasta
id3convert: Kommando nicht gefunden.
id3convert: kommandot finns inte
id3convert: komut yok
id3convert: nie znaleziono polecenia
id3convert: níor aimsíodh an t-ordú
id3convert: no se encontró la orden
id3convert: no s'ha trobat l'ordre
id3convert: opdracht niet gevonden
id3convert: parancs nem található
id3convert: perintah tidak ditemukan
id3convert: príkaz nenájdený
id3convert: příkaz nenalezen
id3convert: команда не найдена
id3convert: командата не е открита
id3convert: 命令找不到
id3convert: コマンドが見つかりません