playmus: 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/playmus - from package: SDL_mixer

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

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