mpdtrace.py: 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/mpdtrace.py - from package: mpich2

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

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